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13 daysnet: ipconfig: Replace strncpy with strscpy in ic_proto_nameThorsten Blum1-1/+2
strncpy() is deprecated [1] for NUL-terminated destination buffers because it does not guarantee NUL termination. Replace it with strscpy() to ensure the destination buffer is always NUL-terminated and to avoid any additional NUL padding. Although the identifier buffer has 252 usable bytes, strncpy() copied only up to 251 bytes to the zero-initialized buffer, relying on the last byte to act as an implicit NUL terminator. Switching to strscpy() avoids this implicit behavior and does not use magic numbers. The source string is also NUL-terminated and satisfies the __must_be_cstr() requirement of strscpy(). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Link: https://patch.msgid.link/20251126220804.102160-2-thorsten.blum@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
13 daysMerge tag 'nf-next-25-11-28' of ↵Jakub Kicinski1-0/+25
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following batch contains Netfilter updates for net-next: 0) Add sanity check for maximum encapsulations in bridge vlan, reported by the new AI robot. 1) Move the flowtable path discovery code to its own file, the nft_flow_offload.c mixes the nf_tables evaluation with the path discovery logic, just split this in two for clarity. 2) Consolidate flowtable xmit path by using dev_queue_xmit() and the real device behind the layer 2 vlan/pppoe device. This allows to inline encapsulation. After this update, hw_ifidx can be removed since both ifidx and hw_ifidx now point to the same device. 3) Support for IPIP encapsulation in the flowtable, extend selftest to cover for this new layer 3 offload, from Lorenzo Bianconi. 4) Push down the skb into the conncount API to fix duplicates in the conncount list for packets with non-confirmed conntrack entries, this is due to an optimization introduced in d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC"). From Fernando Fernandez Mancera. 5) In conncount, disable BH when performing garbage collection to consolidate existing behaviour in the conncount API, also from Fernando. 6) A matching packet with a confirmed conntrack invokes GC if conncount reaches the limit in an attempt to release slots. This allows the existing extensions to be used for real conntrack counting, not just limiting new connections, from Fernando. 7) Support for updating ct count objects in nf_tables, from Fernando. 8) Extend nft_flowtables.sh selftest to send IPv6 TCP traffic, from Lorenzo Bianconi. 9) Fixes for UAPI kernel-doc documentation, from Randy Dunlap. * tag 'nf-next-25-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_tables: improve UAPI kernel-doc comments netfilter: ip6t_srh: fix UAPI kernel-doc comments format selftests: netfilter: nft_flowtable.sh: Add the capability to send IPv6 TCP traffic netfilter: nft_connlimit: add support to object update operation netfilter: nft_connlimit: update the count if add was skipped netfilter: nf_conncount: make nf_conncount_gc_list() to disable BH netfilter: nf_conncount: rework API to use sk_buff directly selftests: netfilter: nft_flowtable.sh: Add IPIP flowtable selftest netfilter: flowtable: Add IPIP tx sw acceleration netfilter: flowtable: Add IPIP rx sw acceleration netfilter: flowtable: use tuple address to calculate next hop netfilter: flowtable: remove hw_ifidx netfilter: flowtable: inline pppoe encapsulation in xmit path netfilter: flowtable: inline vlan encapsulation in xmit path netfilter: flowtable: consolidate xmit path netfilter: flowtable: move path discovery infrastructure to its own file netfilter: flowtable: check for maximum number of encapsulations in bridge vlan ==================== Link: https://patch.msgid.link/20251128002345.29378-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-27netmem, devmem, tcp: access pp fields through @desc in net_iovByungchul Park1-1/+1
Convert all the legacy code directly accessing the pp fields in net_iov to access them through @desc in net_iov. Signed-off-by: Byungchul Park <byungchul@sk.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-28netfilter: flowtable: Add IPIP rx sw accelerationLorenzo Bianconi1-0/+25
Introduce sw acceleration for rx path of IPIP tunnels relying on the netfilter flowtable infrastructure. Subsequent patches will add sw acceleration for IPIP tunnels tx path. This series introduces basic infrastructure to accelerate other tunnel types (e.g. IP6IP6). IPIP rx sw acceleration can be tested running the following scenario where the traffic is forwarded between two NICs (eth0 and eth1) and an IPIP tunnel is used to access a remote site (using eth1 as the underlay device): ETH0 -- TUN0 <==> ETH1 -- [IP network] -- TUN1 (192.168.100.2) $ip addr show 6: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:00:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet 192.168.0.2/24 scope global eth0 valid_lft forever preferred_lft forever 7: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 00:11:22:33:11:55 brd ff:ff:ff:ff:ff:ff inet 192.168.1.1/24 scope global eth1 valid_lft forever preferred_lft forever 8: tun0@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1480 qdisc noqueue state UNKNOWN group default qlen 1000 link/ipip 192.168.1.1 peer 192.168.1.2 inet 192.168.100.1/24 scope global tun0 valid_lft forever preferred_lft forever $ip route show default via 192.168.100.2 dev tun0 192.168.0.0/24 dev eth0 proto kernel scope link src 192.168.0.2 192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.1 192.168.100.0/24 dev tun0 proto kernel scope link src 192.168.100.1 $nft list ruleset table inet filter { flowtable ft { hook ingress priority filter devices = { eth0, eth1 } } chain forward { type filter hook forward priority filter; policy accept; meta l4proto { tcp, udp } flow add @ft } } Reproducing the scenario described above using veths I got the following results: - TCP stream received from the IPIP tunnel: - net-next: (baseline) ~ 71Gbps - net-next + IPIP flowtbale support: ~101Gbps Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-11-25tcp: remove icsk->icsk_retransmit_timerEric Dumazet2-8/+6
Now sk->sk_timer is no longer used by TCP keepalive, we can use its storage for TCP and MPTCP retransmit timers for better cache locality. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251124175013.1473655-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-25tcp: introduce icsk->icsk_keepalive_timerEric Dumazet4-11/+12
sk->sk_timer has been used for TCP keepalives. Keepalive timers are not in fast path, we want to use sk->sk_timer storage for retransmit timers, for better cache locality. Create icsk->icsk_keepalive_timer and change keepalive code to no longer use sk->sk_timer. Added space is reclaimed in the following patch. This includes changes to MPTCP, which was also using sk_timer. Alias icsk->mptcp_tout_timer and icsk->icsk_keepalive_timer for inet_sk_diag_fill() sake. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251124175013.1473655-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-25tcp: rename icsk_timeout() to tcp_timeout_expires()Eric Dumazet3-7/+7
In preparation of sk->tcp_timeout_timer introduction, rename icsk_timeout() helper and change its argument to plain 'const struct sock *sk'. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251124175013.1473655-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-25tools: ynl-gen: add regeneration commentAsbjørn Sloth Tønnesen2-0/+2
Add a comment on regeneration to the generated files. The comment is placed after the YNL-GEN line[1], as to not interfere with ynl-regen.sh's detection logic. [1] and after the optional YNL-ARG line. Link: https://lore.kernel.org/r/aR5m174O7pklKrMR@zx2c4.com/ Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251120174429.390574-3-ast@fiberby.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-24net: factor-out _sk_charge() helperPaolo Abeni1-16/+1
Move out of __inet_accept() the code dealing charging newly accepted socket to memcg. MPTCP will soon use it to on a per subflow basis, in different contexts. No functional changes intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Geliang Tang <geliang@kernel.org> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251121-net-next-mptcp-memcg-backlog-imp-v1-1-1f34b6c1e0b1@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20tcp: add net.ipv4.tcp_rcvbuf_low_rttEric Dumazet3-4/+24
This is a follow up of commit aa251c84636c ("tcp: fix too slow tcp_rcvbuf_grow() action") which brought again the issue that I tried to fix in commit 65c5287892e9 ("tcp: fix sk_rcvbuf overshoot") We also recently increased tcp_rmem[2] to 32 MB in commit 572be9bf9d0d ("tcp: increase tcp_rmem[2] to 32 MB") Idea of this patch is to not let tcp_rcvbuf_grow() grow sk->sk_rcvbuf too fast for small RTT flows. If sk->sk_rcvbuf is too big, this can force NIC driver to not recycle pages from their page pool, and also can cause cache evictions for DDIO enabled cpus/NIC, as receivers are usually slower than senders. Add net.ipv4.tcp_rcvbuf_low_rtt sysctl, set by default to 1000 usec (1 ms) If RTT if smaller than the sysctl value, use the RTT/tcp_rcvbuf_low_rtt ratio to control sk_rcvbuf inflation. Tested: Pair of hosts with a 200Gbit IDPF NIC. Using netperf/netserver Client initiates 8 TCP bulk flows, asking netserver to use CPU #10 only. super_netperf 8 -H server -T,10 -l 30 On server, use perf -e tcp:tcp_rcvbuf_grow while test is running. Before: sysctl -w net.ipv4.tcp_rcvbuf_low_rtt=1 perf record -a -e tcp:tcp_rcvbuf_grow sleep 30 ; perf script|tail -20|cut -c30-230 1153.051201: tcp:tcp_rcvbuf_grow: time=398 rtt_us=382 copied=6905856 inq=180224 space=6115328 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25600000 famil 1153.138752: tcp:tcp_rcvbuf_grow: time=446 rtt_us=413 copied=5529600 inq=180224 space=4505600 ooo=0 scaling_ratio=240 rcvbuf=23068672 rcv_ssthresh=21571860 window_clamp=21626880 rcv_wnd=21286912 famil 1153.361484: tcp:tcp_rcvbuf_grow: time=415 rtt_us=380 copied=7061504 inq=204800 space=6725632 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25600000 famil 1153.457642: tcp:tcp_rcvbuf_grow: time=483 rtt_us=421 copied=5885952 inq=720896 space=4407296 ooo=0 scaling_ratio=240 rcvbuf=23763511 rcv_ssthresh=22223271 window_clamp=22278291 rcv_wnd=21430272 famil 1153.466002: tcp:tcp_rcvbuf_grow: time=308 rtt_us=281 copied=3244032 inq=180224 space=2883584 ooo=0 scaling_ratio=240 rcvbuf=44854314 rcv_ssthresh=41992059 window_clamp=42050919 rcv_wnd=41713664 famil 1153.747792: tcp:tcp_rcvbuf_grow: time=394 rtt_us=332 copied=4460544 inq=585728 space=3063808 ooo=0 scaling_ratio=240 rcvbuf=44854314 rcv_ssthresh=41992059 window_clamp=42050919 rcv_wnd=41373696 famil 1154.260747: tcp:tcp_rcvbuf_grow: time=652 rtt_us=226 copied=10977280 inq=737280 space=9486336 ooo=0 scaling_ratio=240 rcvbuf=31165538 rcv_ssthresh=29197743 window_clamp=29217691 rcv_wnd=28368896 fami 1154.375019: tcp:tcp_rcvbuf_grow: time=461 rtt_us=443 copied=7573504 inq=507904 space=6856704 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25288704 famil 1154.463072: tcp:tcp_rcvbuf_grow: time=494 rtt_us=408 copied=7983104 inq=200704 space=7065600 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25579520 famil 1154.474658: tcp:tcp_rcvbuf_grow: time=507 rtt_us=459 copied=5586944 inq=540672 space=4718592 ooo=0 scaling_ratio=240 rcvbuf=17852266 rcv_ssthresh=16692999 window_clamp=16736499 rcv_wnd=16056320 famil 1154.584657: tcp:tcp_rcvbuf_grow: time=494 rtt_us=427 copied=8126464 inq=204800 space=7782400 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25878235 window_clamp=25937095 rcv_wnd=25600000 famil 1154.702117: tcp:tcp_rcvbuf_grow: time=480 rtt_us=406 copied=5734400 inq=180224 space=5349376 ooo=0 scaling_ratio=240 rcvbuf=23068672 rcv_ssthresh=21571860 window_clamp=21626880 rcv_wnd=21286912 famil 1155.941595: tcp:tcp_rcvbuf_grow: time=717 rtt_us=670 copied=11042816 inq=3784704 space=7159808 ooo=0 scaling_ratio=240 rcvbuf=19581357 rcv_ssthresh=18333222 window_clamp=18357522 rcv_wnd=14614528 fam 1156.384735: tcp:tcp_rcvbuf_grow: time=529 rtt_us=473 copied=9011200 inq=180224 space=7258112 ooo=0 scaling_ratio=240 rcvbuf=19581357 rcv_ssthresh=18333222 window_clamp=18357522 rcv_wnd=18018304 famil 1157.821676: tcp:tcp_rcvbuf_grow: time=529 rtt_us=272 copied=8224768 inq=602112 space=6545408 ooo=0 scaling_ratio=240 rcvbuf=67000000 rcv_ssthresh=62793576 window_clamp=62812500 rcv_wnd=62115840 famil 1158.906379: tcp:tcp_rcvbuf_grow: time=710 rtt_us=445 copied=11845632 inq=540672 space=10240000 ooo=0 scaling_ratio=240 rcvbuf=31165538 rcv_ssthresh=29205935 window_clamp=29217691 rcv_wnd=28536832 fam 1164.600160: tcp:tcp_rcvbuf_grow: time=841 rtt_us=430 copied=12976128 inq=1290240 space=11304960 ooo=0 scaling_ratio=240 rcvbuf=31165538 rcv_ssthresh=29212591 window_clamp=29217691 rcv_wnd=27856896 fa 1165.163572: tcp:tcp_rcvbuf_grow: time=845 rtt_us=800 copied=12632064 inq=540672 space=7921664 ooo=0 scaling_ratio=240 rcvbuf=27666235 rcv_ssthresh=25912795 window_clamp=25937095 rcv_wnd=25260032 fami 1165.653464: tcp:tcp_rcvbuf_grow: time=388 rtt_us=309 copied=4493312 inq=180224 space=3874816 ooo=0 scaling_ratio=240 rcvbuf=44854314 rcv_ssthresh=41995899 window_clamp=42050919 rcv_wnd=41713664 famil 1166.651211: tcp:tcp_rcvbuf_grow: time=556 rtt_us=553 copied=6328320 inq=540672 space=5554176 ooo=0 scaling_ratio=240 rcvbuf=23068672 rcv_ssthresh=21571860 window_clamp=21626880 rcv_wnd=20946944 famil After: sysctl -w net.ipv4.tcp_rcvbuf_low_rtt=1000 perf record -a -e tcp:tcp_rcvbuf_grow sleep 30 ; perf script|tail -20|cut -c30-230 1457.053149: tcp:tcp_rcvbuf_grow: time=128 rtt_us=24 copied=1441792 inq=40960 space=1269760 ooo=0 scaling_ratio=240 rcvbuf=2960741 rcv_ssthresh=2605474 window_clamp=2775694 rcv_wnd=2568192 family=AF_I 1458.000778: tcp:tcp_rcvbuf_grow: time=128 rtt_us=31 copied=1441792 inq=24576 space=1400832 ooo=0 scaling_ratio=240 rcvbuf=3060163 rcv_ssthresh=2810042 window_clamp=2868902 rcv_wnd=2674688 family=AF_I 1458.088059: tcp:tcp_rcvbuf_grow: time=190 rtt_us=110 copied=3227648 inq=385024 space=2781184 ooo=0 scaling_ratio=240 rcvbuf=6728240 rcv_ssthresh=6252705 window_clamp=6307725 rcv_wnd=5799936 family=AF 1458.148549: tcp:tcp_rcvbuf_grow: time=232 rtt_us=129 copied=3956736 inq=237568 space=2842624 ooo=0 scaling_ratio=240 rcvbuf=6731333 rcv_ssthresh=6252705 window_clamp=6310624 rcv_wnd=5918720 family=AF 1458.466861: tcp:tcp_rcvbuf_grow: time=193 rtt_us=83 copied=2949120 inq=180224 space=2457600 ooo=0 scaling_ratio=240 rcvbuf=5751438 rcv_ssthresh=5357689 window_clamp=5391973 rcv_wnd=5054464 family=AF_ 1458.775476: tcp:tcp_rcvbuf_grow: time=257 rtt_us=127 copied=4304896 inq=352256 space=3346432 ooo=0 scaling_ratio=240 rcvbuf=8067131 rcv_ssthresh=7523275 window_clamp=7562935 rcv_wnd=7061504 family=AF 1458.776631: tcp:tcp_rcvbuf_grow: time=200 rtt_us=96 copied=3260416 inq=143360 space=2768896 ooo=0 scaling_ratio=240 rcvbuf=6397256 rcv_ssthresh=5938567 window_clamp=5997427 rcv_wnd=5828608 family=AF_ 1459.707973: tcp:tcp_rcvbuf_grow: time=215 rtt_us=96 copied=2506752 inq=163840 space=1388544 ooo=0 scaling_ratio=240 rcvbuf=3068867 rcv_ssthresh=2768282 window_clamp=2877062 rcv_wnd=2555904 family=AF_ 1460.246494: tcp:tcp_rcvbuf_grow: time=231 rtt_us=80 copied=3756032 inq=204800 space=3117056 ooo=0 scaling_ratio=240 rcvbuf=7288091 rcv_ssthresh=6773725 window_clamp=6832585 rcv_wnd=6471680 family=AF_ 1460.714596: tcp:tcp_rcvbuf_grow: time=270 rtt_us=110 copied=4714496 inq=311296 space=3719168 ooo=0 scaling_ratio=240 rcvbuf=8957739 rcv_ssthresh=8339020 window_clamp=8397880 rcv_wnd=7933952 family=AF 1462.029977: tcp:tcp_rcvbuf_grow: time=101 rtt_us=19 copied=1105920 inq=40960 space=1036288 ooo=0 scaling_ratio=240 rcvbuf=2338970 rcv_ssthresh=2091684 window_clamp=2192784 rcv_wnd=1986560 family=AF_I 1462.802385: tcp:tcp_rcvbuf_grow: time=89 rtt_us=45 copied=1069056 inq=0 space=1064960 ooo=0 scaling_ratio=240 rcvbuf=2338970 rcv_ssthresh=2091684 window_clamp=2192784 rcv_wnd=2035712 family=AF_INET6 1462.918648: tcp:tcp_rcvbuf_grow: time=105 rtt_us=33 copied=1441792 inq=180224 space=1069056 ooo=0 scaling_ratio=240 rcvbuf=2383282 rcv_ssthresh=2091684 window_clamp=2234326 rcv_wnd=1896448 family=AF_ 1463.222533: tcp:tcp_rcvbuf_grow: time=273 rtt_us=144 copied=4603904 inq=385024 space=3469312 ooo=0 scaling_ratio=240 rcvbuf=8422564 rcv_ssthresh=7891053 window_clamp=7896153 rcv_wnd=7409664 family=AF 1466.519312: tcp:tcp_rcvbuf_grow: time=130 rtt_us=23 copied=1343488 inq=0 space=1261568 ooo=0 scaling_ratio=240 rcvbuf=2780158 rcv_ssthresh=2493778 window_clamp=2606398 rcv_wnd=2494464 family=AF_INET6 1466.681003: tcp:tcp_rcvbuf_grow: time=128 rtt_us=21 copied=1441792 inq=12288 space=1343488 ooo=0 scaling_ratio=240 rcvbuf=2932027 rcv_ssthresh=2578555 window_clamp=2748775 rcv_wnd=2568192 family=AF_I 1470.689959: tcp:tcp_rcvbuf_grow: time=255 rtt_us=122 copied=3932160 inq=204800 space=3551232 ooo=0 scaling_ratio=240 rcvbuf=8182038 rcv_ssthresh=7647384 window_clamp=7670660 rcv_wnd=7442432 family=AF 1471.754154: tcp:tcp_rcvbuf_grow: time=188 rtt_us=95 copied=2138112 inq=577536 space=1429504 ooo=0 scaling_ratio=240 rcvbuf=3113650 rcv_ssthresh=2806426 window_clamp=2919046 rcv_wnd=2248704 family=AF_ 1476.813542: tcp:tcp_rcvbuf_grow: time=269 rtt_us=99 copied=3088384 inq=180224 space=2564096 ooo=0 scaling_ratio=240 rcvbuf=6219470 rcv_ssthresh=5771893 window_clamp=5830753 rcv_wnd=5509120 family=AF_ 1477.738309: tcp:tcp_rcvbuf_grow: time=166 rtt_us=54 copied=1777664 inq=180224 space=1417216 ooo=0 scaling_ratio=240 rcvbuf=3117118 rcv_ssthresh=2874958 window_clamp=2922298 rcv_wnd=2613248 family=AF_ We can see sk_rcvbuf values are much smaller, and that rtt_us (estimation of rtt from a receiver point of view) is kept small, instead of being bloated. No difference in throughput. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Tested-by: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/20251119084813.3684576-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-2/+4
Cross-merge networking fixes after downstream PR (net-6.18-rc7). No conflicts, adjacent changes: tools/testing/selftests/net/af_unix/Makefile e1bb28bf13f4 ("selftest: af_unix: Add test for SO_PEEK_OFF.") 45a1cd8346ca ("selftests: af_unix: Add tests for ECONNRESET and EOF semantics") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-18tcp: Don't reinitialise tw->tw_transparent in tcp_time_wait().Kuniyuki Iwashima1-1/+0
tw->tw_transparent is initialised twice in inet_twsk_alloc() and tcp_time_wait(). Let's remove the latter. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20251118000445.4091280-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-18Merge tag 'ipsec-2025-11-18' of ↵Jakub Kicinski1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2025-11-18 1) Misc fixes for xfrm_state creation/modification/deletion. Patchset from Sabrina Dubroca. 2) Fix inner packet family determination for xfrm offloads. From Jianbo Liu. 3) Don't push locally generated packets directly to L2 tunnel mode offloading, they still need processing from the standard xfrm path. From Jianbo Liu. 4) Fix memory leaks in xfrm_add_acquire for policy offloads and policy security contexts. From Zilin Guan. * tag 'ipsec-2025-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: fix memory leak in xfrm_add_acquire() xfrm: Prevent locally generated packets from direct output in tunnel mode xfrm: Determine inner GSO type from packet inner protocol xfrm: Check inner packet family directly from skb_dst xfrm: check all hash buckets for leftover states during netns deletion xfrm: set err and extack on failure to create pcpu SA xfrm: call xfrm_dev_state_delete when xfrm_state_migrate fails to add the state xfrm: make state as DEAD before final put when migrate fails xfrm: also call xfrm_state_delete_tunnel at destroy time for states that were never added xfrm: drop SA reference in xfrm_state_update if dir doesn't match ==================== Link: https://patch.msgid.link/20251118085344.2199815-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-17tcp: reduce tcp_comp_sack_slack_ns default value to 10 usecEric Dumazet1-1/+1
net.ipv4.tcp_comp_sack_slack_ns current default value is too high. When a flow has many drops (1 % or more), and small RTT, adding 100 usec before sending SACK stalls the sender relying on getting SACK fast enough to keep the pipe busy. Decrease the default to 10 usec. This is orthogonal to Congestion Control heuristics to determine if drops are caused by congestion or not. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251114135141.3810964-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-14tcp: gro: inline tcp_gro_pull_header()Eric Dumazet1-27/+0
tcp_gro_pull_header() is used in GRO fast path, inline it. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251113140358.58242-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+5
Cross-merge networking fixes after downstream PR (net-6.18-rc6). No conflicts, adjacent changes in: drivers/net/phy/micrel.c 96a9178a29a6 ("net: phy: micrel: lan8814 fix reset of the QSGMII interface") 61b7ade9ba8c ("net: phy: micrel: Add support for non PTP SKUs for lan8814") and a trivial one in tools/testing/selftests/drivers/net/Makefile. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-12ipv4: route: Prevent rt_bind_exception() from rebinding stale fnheChuang Wang1-0/+5
The sit driver's packet transmission path calls: sit_tunnel_xmit() -> update_or_create_fnhe(), which lead to fnhe_remove_oldest() being called to delete entries exceeding FNHE_RECLAIM_DEPTH+random. The race window is between fnhe_remove_oldest() selecting fnheX for deletion and the subsequent kfree_rcu(). During this time, the concurrent path's __mkroute_output() -> find_exception() can fetch the soon-to-be-deleted fnheX, and rt_bind_exception() then binds it with a new dst using a dst_hold(). When the original fnheX is freed via RCU, the dst reference remains permanently leaked. CPU 0 CPU 1 __mkroute_output() find_exception() [fnheX] update_or_create_fnhe() fnhe_remove_oldest() [fnheX] rt_bind_exception() [bind dst] RCU callback [fnheX freed, dst leak] This issue manifests as a device reference count leak and a warning in dmesg when unregistering the net device: unregister_netdevice: waiting for sitX to become free. Usage count = N Ido Schimmel provided the simple test validation method [1]. The fix clears 'oldest->fnhe_daddr' before calling fnhe_flush_routes(). Since rt_bind_exception() checks this field, setting it to zero prevents the stale fnhe from being reused and bound to a new dst just before it is freed. [1] ip netns add ns1 ip -n ns1 link set dev lo up ip -n ns1 address add 192.0.2.1/32 dev lo ip -n ns1 link add name dummy1 up type dummy ip -n ns1 route add 192.0.2.2/32 dev dummy1 ip -n ns1 link add name gretap1 up arp off type gretap \ local 192.0.2.1 remote 192.0.2.2 ip -n ns1 route add 198.51.0.0/16 dev gretap1 taskset -c 0 ip netns exec ns1 mausezahn gretap1 \ -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q & taskset -c 2 ip netns exec ns1 mausezahn gretap1 \ -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q & sleep 10 ip netns pids ns1 | xargs kill ip netns del ns1 Cc: stable@vger.kernel.org Fixes: 67d6d681e15b ("ipv4: make exception cache less predictible") Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251111064328.24440-1-nashuiliang@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-10net/smc: bpf: Introduce generic hook for handshake flowD. Wythe1-14/+17
The introduction of IPPROTO_SMC enables eBPF programs to determine whether to use SMC based on the context of socket creation, such as network namespaces, PID and comm name, etc. As a subsequent enhancement, to introduce a new generic hook that allows decisions on whether to use SMC or not at runtime, including but not limited to local/remote IP address or ports. User can write their own implememtion via bpf_struct_ops now to choose whether to use SMC or not before TCP 3rd handshake to be comleted. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Dust Li <dust.li@linux.alibaba.com> Link: https://patch.msgid.link/20251107035632.115950-3-alibuda@linux.alibaba.com
2025-11-07tcp: add net.ipv4.tcp_comp_sack_rtt_percentEric Dumazet3-8/+28
TCP SACK compression has been added in 2018 in commit 5d9f4262b7ea ("tcp: add SACK compression"). It is working great for WAN flows (with large RTT). Wifi in particular gets a significant boost _when_ ACK are suppressed. Add a new sysctl so that we can tune the very conservative 5 % value that has been used so far in this formula, so that small RTT flows can benefit from this feature. delay = min ( 5 % of RTT, 1 ms) This patch adds new tcp_comp_sack_rtt_percent sysctl to ease experiments and tuning. Given that we cap the delay to 1ms (tcp_comp_sack_delay_ns sysctl), set the default value to 33 %. Quoting Neal Cardwell ( https://lore.kernel.org/netdev/CADVnQymZ1tFnEA1Q=vtECs0=Db7zHQ8=+WCQtnhHFVbEOzjVnQ@mail.gmail.com/ ) The rationale for 33% is basically to try to facilitate pipelining, where there are always at least 3 ACKs and 3 GSO/TSO skbs per SRTT, so that the path can maintain a budget for 3 full-sized GSO/TSO skbs "in flight" at all times: + 1 skb in the qdisc waiting to be sent by the NIC next + 1 skb being sent by the NIC (being serialized by the NIC out onto the wire) + 1 skb being received and aggregated by the receiver machine's aggregation mechanism (some combination of LRO, GRO, and sack compression) Note that this is basically the same magic number (3) and the same rationales as: (a) tcp_tso_should_defer() ensuring that we defer sending data for no longer than cwnd/tcp_tso_win_divisor (where tcp_tso_win_divisor = 3), and (b) bbr_quantization_budget() ensuring that cwnd is at least 3 GSO/TSO skbs to maintain pipelining and full throughput at low RTTs Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251106115236.3450026-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-07tcp: Remove timeout arg from reqsk_timeout().Kuniyuki Iwashima2-3/+4
reqsk_timeout() is always called with @timeout being TCP_RTO_MAX. Let's remove the arg. As a prep for the next patch, reqsk_timeout() is moved to tcp.h and renamed to tcp_reqsk_timeout(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251106003357.273403-5-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-07tcp: Remove redundant init for req->num_timeout.Kuniyuki Iwashima1-2/+0
Commit 5903123f662e ("tcp: Use BPF timeout setting for SYN ACK RTO") introduced req->timeout and initialised it in 3 places: 1. reqsk_alloc() sets 0 2. inet_reqsk_alloc() sets TCP_TIMEOUT_INIT 3. tcp_conn_request() sets tcp_timeout_init() 1. has been always redundant as 2. overwrites it immediately. 2. was necessary for TFO SYN+ACK but is no longer needed after commit 8ea731d4c2ce ("tcp: Make SYN ACK RTO tunable by BPF programs with TFO"). 3. was moved to reqsk_queue_hash_req() in the previous patch. Now, we always initialise req->timeout just before scheduling the SYN+ACK timer: * For non-TFO SYN+ACK : reqsk_queue_hash_req() * For TFO SYN+ACK : tcp_fastopen_create_child() Let's remove the redundant initialisation of req->timeout in reqsk_alloc() and inet_reqsk_alloc(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251106003357.273403-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-07tcp: Remove timeout arg from reqsk_queue_hash_req().Kuniyuki Iwashima2-15/+10
inet_csk_reqsk_queue_hash_add() is no longer shared by DCCP. We do not need to pass req->timeout down to reqsk_queue_hash_req(). Let's move tcp_timeout_init() from tcp_conn_request() to reqsk_queue_hash_req(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251106003357.273403-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-07tcp: Call tcp_syn_ack_timeout() directly.Kuniyuki Iwashima3-4/+4
Since DCCP has been removed, we do not need to use request_sock_ops.syn_ack_timeout(). Let's call tcp_syn_ack_timeout() directly. Now other function pointers of request_sock_ops are protocol-dependent. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251106003357.273403-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert struct sockaddr to fixed-size "sa_data[14]"Kees Cook1-1/+1
Revert struct sockaddr from flexible array to fixed 14-byte "sa_data", to solve over 36,000 -Wflex-array-member-not-at-end warnings, since struct sockaddr is embedded within many network structs. With socket/proto sockaddr-based internal APIs switched to use struct sockaddr_unsized, there should be no more uses of struct sockaddr that depend on reading beyond the end of struct sockaddr::sa_data that might trigger bounds checking. Comparing an x86_64 "allyesconfig" vmlinux build before and after this patch showed no new "ud1" instructions from CONFIG_UBSAN_BOUNDS nor any new "field-spanning" memcpy CONFIG_FORTIFY_SOURCE instrumentations. Cc: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-8-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04bpf: Convert cgroup sockaddr filters to use sockaddr_unsized consistentlyKees Cook1-2/+2
Update BPF cgroup sockaddr filtering infrastructure to use sockaddr_unsized consistently throughout the call chain, removing redundant explicit casts from callers. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-6-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert proto callbacks from sockaddr to sockaddr_unsizedKees Cook6-18/+21
Convert struct proto pre_connect(), connect(), bind(), and bind_add() callback function prototypes from struct sockaddr to struct sockaddr_unsized. This does not change per-implementation use of sockaddr for passing around an arbitrarily sized sockaddr struct. Those will be addressed in future patches. Additionally removes the no longer referenced struct sockaddr from include/net/inet_common.h. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-5-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert proto_ops connect() callbacks to use sockaddr_unsizedKees Cook3-9/+9
Update all struct proto_ops connect() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert proto_ops bind() callbacks to use sockaddr_unsizedKees Cook2-3/+3
Update all struct proto_ops bind() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-7/+14
Cross-merge networking fixes after downstream PR (net-6.18-rc4). No conflicts, adjacent changes: drivers/net/ethernet/stmicro/stmmac/stmmac_main.c ded9813d17d3 ("net: stmmac: Consider Tx VLAN offload tag length for maxSDU") 26ab9830beab ("net: stmmac: replace has_xxxx with core_type") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-30xfrm: Determine inner GSO type from packet inner protocolJianbo Liu1-2/+4
The GSO segmentation functions for ESP tunnel mode (xfrm4_tunnel_gso_segment and xfrm6_tunnel_gso_segment) were determining the inner packet's L2 protocol type by checking the static x->inner_mode.family field from the xfrm state. This is unreliable. In tunnel mode, the state's actual inner family could be defined by x->inner_mode.family or by x->inner_mode_iaf.family. Checking only the former can lead to a mismatch with the actual packet being processed, causing GSO to create segments with the wrong L2 header type. This patch fixes the bug by deriving the inner mode directly from the packet's inner protocol stored in XFRM_MODE_SKB_CB(skb)->protocol. Instead of replicating the code, this patch modifies the xfrm_ip2inner_mode helper function. It now correctly returns &x->inner_mode if the selector family (x->sel.family) is already specified, thereby handling both specific and AF_UNSPEC cases appropriately. With this change, ESP GSO can use xfrm_ip2inner_mode to get the correct inner mode. It doesn't affect existing callers, as the updated logic now mirrors the checks they were already performing externally. Fixes: 26dbd66eab80 ("esp: choose the correct inner protocol for GSO on inter address family tunnels") Signed-off-by: Jianbo Liu <jianbol@nvidia.com> Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2025-10-29ipv4: icmp: Add RFC 5837 supportIdo Schimmel2-1/+201
Add the ability to append the incoming IP interface information to ICMPv4 error messages in accordance with RFC 5837 and RFC 4884. This is required for more meaningful traceroute results in unnumbered networks. The feature is disabled by default and controlled via a new sysctl ("net.ipv4.icmp_errors_extension_mask") which accepts a bitmask of ICMP extensions to append to ICMP error messages. Currently, only a single value is supported, but the interface and the implementation should be able to support more extensions, if needed. Clone the skb and copy the relevant data portions before modifying the skb as the caller of __icmp_send() still owns the skb after the function returns. This should be fine since by default ICMP error messages are rate limited to 1000 per second and no more than 1 per second per specific host. Trim or pad the packet to 128 bytes before appending the ICMP extension structure in order to be compatible with legacy applications that assume that the ICMP extension structure always starts at this offset (the minimum length specified by RFC 4884). Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251027082232.232571-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29tcp: fix too slow tcp_rcvbuf_grow() actionEric Dumazet1-2/+9
While the blamed commits apparently avoided an overshoot, they also limited how fast a sender can increase BDP at each RTT. This is not exactly a revert, we do not add the 16 * tp->advmss cushion we had, and we are keeping the out_of_order_queue contribution. Do the same in mptcp_rcvbuf_grow(). Tested: emulated 50ms rtt (tcp_stream --tcp-tx-delay 50000), cubic 20 second flow. net.ipv4.tcp_rmem set to "4096 131072 67000000" perf record -a -e tcp:tcp_rcvbuf_grow sleep 20 perf script Before: We can see we fail to roughly double RWIN at each RTT. Sender is RWIN limited while CWND is ramping up (before getting tcp_wmem limited). tcp_stream 33793 [010] 825.717525: tcp:tcp_rcvbuf_grow: time=100869 rtt_us=50428 copied=49152 inq=0 space=40960 ooo=0 scaling_ratio=219 rcvbuf=131072 rcv_ssthresh=103970 window_clamp=112128 rcv_wnd=106496 tcp_stream 33793 [010] 825.768966: tcp:tcp_rcvbuf_grow: time=51447 rtt_us=50362 copied=86016 inq=0 space=49152 ooo=0 scaling_ratio=219 rcvbuf=131072 rcv_ssthresh=107474 window_clamp=112128 rcv_wnd=106496 tcp_stream 33793 [010] 825.821539: tcp:tcp_rcvbuf_grow: time=52577 rtt_us=50243 copied=114688 inq=0 space=86016 ooo=0 scaling_ratio=219 rcvbuf=201096 rcv_ssthresh=167377 window_clamp=172031 rcv_wnd=167936 tcp_stream 33793 [010] 825.871781: tcp:tcp_rcvbuf_grow: time=50248 rtt_us=50237 copied=167936 inq=0 space=114688 ooo=0 scaling_ratio=219 rcvbuf=268129 rcv_ssthresh=224722 window_clamp=229375 rcv_wnd=225280 tcp_stream 33793 [010] 825.922475: tcp:tcp_rcvbuf_grow: time=50698 rtt_us=50183 copied=241664 inq=0 space=167936 ooo=0 scaling_ratio=219 rcvbuf=392617 rcv_ssthresh=331217 window_clamp=335871 rcv_wnd=323584 tcp_stream 33793 [010] 825.973326: tcp:tcp_rcvbuf_grow: time=50855 rtt_us=50213 copied=339968 inq=0 space=241664 ooo=0 scaling_ratio=219 rcvbuf=564986 rcv_ssthresh=478674 window_clamp=483327 rcv_wnd=462848 tcp_stream 33793 [010] 826.023970: tcp:tcp_rcvbuf_grow: time=50647 rtt_us=50248 copied=491520 inq=0 space=339968 ooo=0 scaling_ratio=219 rcvbuf=794811 rcv_ssthresh=671778 window_clamp=679935 rcv_wnd=651264 tcp_stream 33793 [010] 826.074612: tcp:tcp_rcvbuf_grow: time=50648 rtt_us=50227 copied=700416 inq=0 space=491520 ooo=0 scaling_ratio=219 rcvbuf=1149124 rcv_ssthresh=974881 window_clamp=983039 rcv_wnd=942080 tcp_stream 33793 [010] 826.125452: tcp:tcp_rcvbuf_grow: time=50845 rtt_us=50225 copied=987136 inq=8192 space=700416 ooo=0 scaling_ratio=219 rcvbuf=1637502 rcv_ssthresh=1392674 window_clamp=1400831 rcv_wnd=1339392 tcp_stream 33793 [010] 826.175698: tcp:tcp_rcvbuf_grow: time=50250 rtt_us=50198 copied=1347584 inq=0 space=978944 ooo=0 scaling_ratio=219 rcvbuf=2288672 rcv_ssthresh=1949729 window_clamp=1957887 rcv_wnd=1945600 tcp_stream 33793 [010] 826.225947: tcp:tcp_rcvbuf_grow: time=50252 rtt_us=50240 copied=1945600 inq=0 space=1347584 ooo=0 scaling_ratio=219 rcvbuf=3150516 rcv_ssthresh=2687010 window_clamp=2695167 rcv_wnd=2691072 tcp_stream 33793 [010] 826.276175: tcp:tcp_rcvbuf_grow: time=50233 rtt_us=50224 copied=2691072 inq=0 space=1945600 ooo=0 scaling_ratio=219 rcvbuf=4548617 rcv_ssthresh=3883041 window_clamp=3891199 rcv_wnd=3887104 tcp_stream 33793 [010] 826.326403: tcp:tcp_rcvbuf_grow: time=50233 rtt_us=50229 copied=3887104 inq=0 space=2691072 ooo=0 scaling_ratio=219 rcvbuf=6291456 rcv_ssthresh=5370482 window_clamp=5382144 rcv_wnd=5373952 tcp_stream 33793 [010] 826.376723: tcp:tcp_rcvbuf_grow: time=50323 rtt_us=50218 copied=5373952 inq=0 space=3887104 ooo=0 scaling_ratio=219 rcvbuf=9087658 rcv_ssthresh=7755537 window_clamp=7774207 rcv_wnd=7757824 tcp_stream 33793 [010] 826.426991: tcp:tcp_rcvbuf_grow: time=50274 rtt_us=50196 copied=7757824 inq=180224 space=5373952 ooo=0 scaling_ratio=219 rcvbuf=12563759 rcv_ssthresh=10729233 window_clamp=10747903 rcv_wnd=10575872 tcp_stream 33793 [010] 826.477229: tcp:tcp_rcvbuf_grow: time=50241 rtt_us=50078 copied=10731520 inq=180224 space=7577600 ooo=0 scaling_ratio=219 rcvbuf=17715667 rcv_ssthresh=15136529 window_clamp=15155199 rcv_wnd=14983168 tcp_stream 33793 [010] 826.527482: tcp:tcp_rcvbuf_grow: time=50258 rtt_us=50153 copied=15138816 inq=360448 space=10551296 ooo=0 scaling_ratio=219 rcvbuf=24667870 rcv_ssthresh=21073410 window_clamp=21102591 rcv_wnd=20766720 tcp_stream 33793 [010] 826.577712: tcp:tcp_rcvbuf_grow: time=50234 rtt_us=50228 copied=21073920 inq=0 space=14778368 ooo=0 scaling_ratio=219 rcvbuf=34550339 rcv_ssthresh=29517041 window_clamp=29556735 rcv_wnd=29519872 tcp_stream 33793 [010] 826.627982: tcp:tcp_rcvbuf_grow: time=50275 rtt_us=50220 copied=29519872 inq=540672 space=21073920 ooo=0 scaling_ratio=219 rcvbuf=49268707 rcv_ssthresh=42090625 window_clamp=42147839 rcv_wnd=41627648 tcp_stream 33793 [010] 826.678274: tcp:tcp_rcvbuf_grow: time=50296 rtt_us=50185 copied=42053632 inq=761856 space=28979200 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57238168 window_clamp=57316406 rcv_wnd=56606720 tcp_stream 33793 [010] 826.728627: tcp:tcp_rcvbuf_grow: time=50357 rtt_us=50128 copied=43913216 inq=851968 space=41291776 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57290728 window_clamp=57316406 rcv_wnd=56524800 tcp_stream 33793 [010] 827.131364: tcp:tcp_rcvbuf_grow: time=50239 rtt_us=50127 copied=43843584 inq=655360 space=43061248 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57290728 window_clamp=57316406 rcv_wnd=56696832 tcp_stream 33793 [010] 827.181613: tcp:tcp_rcvbuf_grow: time=50254 rtt_us=50115 copied=43843584 inq=524288 space=43188224 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57290728 window_clamp=57316406 rcv_wnd=56807424 tcp_stream 33793 [010] 828.339635: tcp:tcp_rcvbuf_grow: time=50283 rtt_us=50110 copied=43843584 inq=458752 space=43319296 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57290728 window_clamp=57316406 rcv_wnd=56864768 tcp_stream 33793 [010] 828.440350: tcp:tcp_rcvbuf_grow: time=50404 rtt_us=50099 copied=43843584 inq=393216 space=43384832 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57290728 window_clamp=57316406 rcv_wnd=56922112 tcp_stream 33793 [010] 829.195106: tcp:tcp_rcvbuf_grow: time=50154 rtt_us=50077 copied=43843584 inq=196608 space=43450368 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57290728 window_clamp=57316406 rcv_wnd=57090048 After: It takes few steps to increase RWIN. Sender is no longer RWIN limited. tcp_stream 50826 [010] 935.634212: tcp:tcp_rcvbuf_grow: time=100788 rtt_us=50315 copied=49152 inq=0 space=40960 ooo=0 scaling_ratio=219 rcvbuf=131072 rcv_ssthresh=103970 window_clamp=112128 rcv_wnd=106496 tcp_stream 50826 [010] 935.685642: tcp:tcp_rcvbuf_grow: time=51437 rtt_us=50361 copied=86016 inq=0 space=49152 ooo=0 scaling_ratio=219 rcvbuf=160875 rcv_ssthresh=132969 window_clamp=137623 rcv_wnd=131072 tcp_stream 50826 [010] 935.738299: tcp:tcp_rcvbuf_grow: time=52660 rtt_us=50256 copied=139264 inq=0 space=86016 ooo=0 scaling_ratio=219 rcvbuf=502741 rcv_ssthresh=411497 window_clamp=430079 rcv_wnd=413696 tcp_stream 50826 [010] 935.788544: tcp:tcp_rcvbuf_grow: time=50249 rtt_us=50233 copied=307200 inq=0 space=139264 ooo=0 scaling_ratio=219 rcvbuf=728690 rcv_ssthresh=618717 window_clamp=623371 rcv_wnd=618496 tcp_stream 50826 [010] 935.838796: tcp:tcp_rcvbuf_grow: time=50258 rtt_us=50202 copied=618496 inq=0 space=307200 ooo=0 scaling_ratio=219 rcvbuf=2450338 rcv_ssthresh=1855709 window_clamp=2096187 rcv_wnd=1859584 tcp_stream 50826 [010] 935.889140: tcp:tcp_rcvbuf_grow: time=50347 rtt_us=50166 copied=1261568 inq=0 space=618496 ooo=0 scaling_ratio=219 rcvbuf=4376503 rcv_ssthresh=3725291 window_clamp=3743961 rcv_wnd=3706880 tcp_stream 50826 [010] 935.939435: tcp:tcp_rcvbuf_grow: time=50300 rtt_us=50185 copied=2478080 inq=24576 space=1261568 ooo=0 scaling_ratio=219 rcvbuf=9082648 rcv_ssthresh=7733731 window_clamp=7769921 rcv_wnd=7692288 tcp_stream 50826 [010] 935.989681: tcp:tcp_rcvbuf_grow: time=50251 rtt_us=50221 copied=4915200 inq=114688 space=2453504 ooo=0 scaling_ratio=219 rcvbuf=16574936 rcv_ssthresh=14108110 window_clamp=14179339 rcv_wnd=14024704 tcp_stream 50826 [010] 936.039967: tcp:tcp_rcvbuf_grow: time=50289 rtt_us=50279 copied=9830400 inq=114688 space=4800512 ooo=0 scaling_ratio=219 rcvbuf=32695050 rcv_ssthresh=27896187 window_clamp=27969593 rcv_wnd=27815936 tcp_stream 50826 [010] 936.090172: tcp:tcp_rcvbuf_grow: time=50211 rtt_us=50200 copied=19841024 inq=114688 space=9715712 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57245176 window_clamp=57316406 rcv_wnd=57163776 tcp_stream 50826 [010] 936.140430: tcp:tcp_rcvbuf_grow: time=50262 rtt_us=50197 copied=39501824 inq=114688 space=19726336 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57245176 window_clamp=57316406 rcv_wnd=57163776 tcp_stream 50826 [010] 936.190527: tcp:tcp_rcvbuf_grow: time=50101 rtt_us=50071 copied=43655168 inq=262144 space=39387136 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57259192 window_clamp=57316406 rcv_wnd=57032704 tcp_stream 50826 [010] 936.240719: tcp:tcp_rcvbuf_grow: time=50197 rtt_us=50057 copied=43843584 inq=262144 space=43393024 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57259192 window_clamp=57316406 rcv_wnd=57032704 tcp_stream 50826 [010] 936.341271: tcp:tcp_rcvbuf_grow: time=50297 rtt_us=50123 copied=43843584 inq=131072 space=43581440 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57259192 window_clamp=57316406 rcv_wnd=57147392 tcp_stream 50826 [010] 936.642503: tcp:tcp_rcvbuf_grow: time=50131 rtt_us=50084 copied=43843584 inq=0 space=43712512 ooo=0 scaling_ratio=219 rcvbuf=67000000 rcv_ssthresh=57259192 window_clamp=57316406 rcv_wnd=57262080 Fixes: 65c5287892e9 ("tcp: fix sk_rcvbuf overshoot") Fixes: e118cdc34dd1 ("mptcp: rcvbuf auto-tuning improvement") Reported-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/589 Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251028-net-tcp-recv-autotune-v3-4-74b43ba4c84c@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29tcp: add newval parameter to tcp_rcvbuf_grow()Eric Dumazet1-7/+7
This patch has no functional change, and prepares the following one. tcp_rcvbuf_grow() will need to have access to tp->rcvq_space.space old and new values. Change mptcp_rcvbuf_grow() in a similar way. Signed-off-by: Eric Dumazet <edumazet@google.com> [ Moved 'oldval' declaration to the next patch to avoid warnings at build time. ] Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251028-net-tcp-recv-autotune-v3-3-74b43ba4c84c@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29net: ipv4: Remove extern udp_v4_early_demux()/tcp_v4_early_demux() in .c filesWang Liang1-2/+2
Function udp_v4_early_demux() was already declared in 'include/net/udp.h', no need to keep the extern in 'ip_input.c', which may produce the following checkpatch warning: WARNING: externs should be avoided in .c files #45: FILE: net/ipv4/ip_input.c:322: +enum skb_drop_reason udp_v4_early_demux(struct sk_buff *skb); Replace it by including 'net/udp.h'. Do the same for tcp_v4_early_demux(). Signed-off-by: Wang Liang <wangliang74@huawei.com> Link: https://patch.msgid.link/20251025092637.1020960-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-28net: tcp_lp: fix kernel-doc warnings and update outdated reference linksRakuram Eswaran1-2/+5
Fix kernel-doc warnings in tcp_lp.c by adding missing parameter descriptions for tcp_lp_cong_avoid() and tcp_lp_pkts_acked() when building with W=1. Also replace invalid URLs in the file header comment with the currently valid links to the TCP-LP paper and implementation page. No functional changes. Signed-off-by: Rakuram Eswaran <rakuram.e96@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20251025-net_ipv4_tcp_lp_c-v1-1-058cc221499e@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27tcp: remove one ktime_get() from recvmsg() fast pathEric Dumazet2-3/+11
Each time some payload is consumed by user space (recvmsg() and friends), TCP calls tcp_rcv_space_adjust() to run DRS algorithm to check if an increase of sk->sk_rcvbuf is needed. This function is based on time sampling, and currently calls tcp_mstamp_refresh(tp), which is a wrapper around ktime_get_ns(). ktime_get_ns() has a high cost on some platforms. 100+ cycles for rdtscp on AMD EPYC Turin for instance. We do not have to refresh tp->tcp_mpstamp, using the last cached value is enough. We only need to refresh it from __tcp_cleanup_rbuf() if an ACK must be sent (this is a rare event). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251024120707.3516550-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27sctp: Use sctp_clone_sock() in sctp_do_peeloff().Kuniyuki Iwashima1-0/+1
sctp_do_peeloff() calls sock_create() to allocate and initialise struct sock, inet_sock, and sctp_sock, but later sctp_copy_sock() and sctp_sock_migrate() overwrite most fields. What sctp_do_peeloff() does is more like accept(). Let's use sock_create_lite() and sctp_clone_sock(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20251023231751.4168390-8-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-27sctp: Use sk_clone() in sctp_accept().Kuniyuki Iwashima1-3/+1
sctp_accept() calls sctp_v[46]_create_accept_sk() to allocate a new socket and calls sctp_sock_migrate() to copy fields from the parent socket to the new socket. sctp_v4_create_accept_sk() allocates sk by sk_alloc(), initialises it by sock_init_data(), and copy a bunch of fields from the parent socekt by sctp_copy_sock(). sctp_sock_migrate() calls sctp_copy_descendant() to copy most fields in sctp_sock from the parent socket by memcpy(). These can be simply replaced by sk_clone(). Let's consolidate sctp_v[46]_create_accept_sk() to sctp_clone_sock() with sk_clone(). We will reuse sctp_clone_sock() for sctp_do_peeloff() and then remove sctp_copy_descendant(). Note that sock_reset_flag(newsk, SOCK_ZAPPED) is not copied to sctp_clone_sock() as sctp does not use SOCK_ZAPPED at all. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20251023231751.4168390-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-24neighbour: Convert rwlock of struct neigh_table to spinlock.Kuniyuki Iwashima1-2/+2
Only neigh_for_each() and neigh_seq_start/stop() are on the reader side of neigh_table.lock. Let's convert rwlock to the plain spinlock. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251022054004.2514876-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-23tcp: Remove unnecessary null check in tcp_inbound_md5_hash()Eric Biggers1-6/+4
The 'if (!key && hash_location)' check in tcp_inbound_md5_hash() implies that hash_location might be null. However, later code in the function dereferences hash_location anyway, without checking for null first. Fortunately, there is no real bug, since tcp_inbound_md5_hash() is called only with non-null values of hash_location. Therefore, remove the unnecessary and misleading null check of hash_location. This silences a Smatch static checker warning (https://lore.kernel.org/netdev/aPi4b6aWBbBR52P1@stanley.mountain/) Also fix the related comment at the beginning of the function. Signed-off-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Link: https://patch.msgid.link/20251022221209.19716-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17Merge tag 'for-netdev' of ↵Jakub Kicinski4-27/+30
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Martin KaFai Lau says: ==================== pull-request: bpf-next 2025-10-16 We've added 6 non-merge commits during the last 1 day(s) which contain a total of 18 files changed, 577 insertions(+), 38 deletions(-). The main changes are: 1) Bypass the global per-protocol memory accounting either by setting a netns sysctl or using bpf_setsockopt in a bpf program, from Kuniyuki Iwashima. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: selftests/bpf: Add test for sk->sk_bypass_prot_mem. bpf: Introduce SK_BPF_BYPASS_PROT_MEM. bpf: Support bpf_setsockopt() for BPF_CGROUP_INET_SOCK_CREATE. net: Introduce net.core.bypass_prot_mem sysctl. net: Allow opt-out from global protocol memory accounting. tcp: Save lock_sock() for memcg in inet_csk_accept(). ==================== Link: https://patch.msgid.link/20251016204539.773707-1-martin.lau@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17tcp: Convert tcp-md5 to use MD5 library instead of crypto_ahashEric Biggers4-140/+76
Make tcp-md5 use the MD5 library API (added in 6.18) instead of the crypto_ahash API. This is much simpler and also more efficient: - The library API just operates on struct md5_ctx. Just allocate this struct on the stack instead of using a pool of pre-allocated crypto_ahash and ahash_request objects. - The library API accepts standard pointers and doesn't require scatterlists. So, for hashing the headers just use an on-stack buffer instead of a pool of pre-allocated kmalloc'ed scratch buffers. - The library API never fails. Therefore, checking for MD5 hashing errors is no longer necessary. Update tcp_v4_md5_hash_skb(), tcp_v6_md5_hash_skb(), tcp_v4_md5_hash_hdr(), tcp_v6_md5_hash_hdr(), tcp_md5_hash_key(), tcp_sock_af_ops::calc_md5_hash, and tcp_request_sock_ops::calc_md5_hash to return void instead of int. - The library API provides direct access to the MD5 code, eliminating unnecessary overhead such as indirect function calls and scatterlist management. Microbenchmarks of tcp_v4_md5_hash_skb() on x86_64 show a speedup from 7518 to 7041 cycles (6% fewer) with skb->len == 1440, or from 1020 to 678 cycles (33% fewer) with skb->len == 140. Since tcp_sigpool_hash_skb_data() can no longer be used, add a function tcp_md5_hash_skb_data() which is specialized to MD5. Of course, to the extent that this duplicates any code, it's well worth it. To preserve the existing behavior of TCP-MD5 support being disabled when the kernel is booted with "fips=1", make tcp_md5_do_add() check fips_enabled itself. Previously it relied on the error from crypto_alloc_ahash("md5") being bubbled up. I don't know for sure that this is actually needed, but this preserves the existing behavior. Tested with bidirectional TCP-MD5, both IPv4 and IPv6, between a kernel that includes this commit and a kernel that doesn't include this commit. (Side note: please don't use TCP-MD5! It's cryptographically weak. But as long as Linux supports it, it might as well be implemented properly.) Signed-off-by: Eric Biggers <ebiggers@kernel.org> Link: https://patch.msgid.link/20251014215836.115616-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17inet: Avoid ehash lookup race in inet_twsk_hashdance_schedule()Xuanqiang Luo1-23/+12
Since ehash lookups are lockless, if another CPU is converting sk to tw concurrently, fetching the newly inserted tw with tw->tw_refcnt == 0 cause lookup failure. The call trace map is drawn as follows: CPU 0 CPU 1 ----- ----- inet_twsk_hashdance_schedule() spin_lock() inet_twsk_add_node_rcu(tw, ...) __inet_lookup_established() (find tw, failure due to tw_refcnt = 0) __sk_nulls_del_node_init_rcu(sk) refcount_set(&tw->tw_refcnt, 3) spin_unlock() By replacing sk with tw atomically via hlist_nulls_replace_init_rcu() after setting tw_refcnt, we ensure that tw is either fully initialized or not visible to other CPUs, eliminating the race. It's worth noting that we held lock_sock() before the replacement, so there's no need to check if sk is hashed. Thanks to Kuniyuki Iwashima! Fixes: 3ab5aee7fe84 ("net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls") Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251015020236.431822-4-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-17inet: Avoid ehash lookup race in inet_ehash_insert()Xuanqiang Luo1-2/+6
Since ehash lookups are lockless, if one CPU performs a lookup while another concurrently deletes and inserts (removing reqsk and inserting sk), the lookup may fail to find the socket, an RST may be sent. The call trace map is drawn as follows: CPU 0 CPU 1 ----- ----- inet_ehash_insert() spin_lock() sk_nulls_del_node_init_rcu(osk) __inet_lookup_established() (lookup failed) __sk_nulls_add_node_rcu(sk, list) spin_unlock() As both deletion and insertion operate on the same ehash chain, this patch introduces a new sk_nulls_replace_node_init_rcu() helper functions to implement atomic replacement. Fixes: 5e0724d027f0 ("tcp/dccp: fix hashdance race for passive sessions") Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251015020236.431822-3-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-16net: Allow opt-out from global protocol memory accounting.Kuniyuki Iwashima2-2/+8
Some protocols (e.g., TCP, UDP) implement memory accounting for socket buffers and charge memory to per-protocol global counters pointed to by sk->sk_proto->memory_allocated. Sometimes, system processes do not want that limitation. For a similar purpose, there is SO_RESERVE_MEM for sockets under memcg. Also, by opting out of the per-protocol accounting, sockets under memcg can avoid paying costs for two orthogonal memory accounting mechanisms. A microbenchmark result is in the subsequent bpf patch. Let's allow opt-out from the per-protocol memory accounting if sk->sk_bypass_prot_mem is true. sk->sk_bypass_prot_mem and sk->sk_prot are placed in the same cache line, and sk_has_account() always fetches sk->sk_prot before accessing sk->sk_bypass_prot_mem, so there is no extra cache miss for this patch. The following patches will set sk->sk_bypass_prot_mem to true, and then, the per-protocol memory accounting will be skipped. Note that this does NOT disable memcg, but rather the per-protocol one. Another option not to use the hole in struct sock_common is create sk_prot variants like tcp_prot_bypass, but this would complicate SOCKMAP logic, tcp_bpf_prots etc. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://patch.msgid.link/20251014235604.3057003-3-kuniyu@google.com
2025-10-16tcp: Save lock_sock() for memcg in inet_csk_accept().Kuniyuki Iwashima2-25/+22
If memcg is enabled, accept() acquires lock_sock() twice for each new TCP/MPTCP socket in inet_csk_accept() and __inet_accept(). Let's move memcg operations from inet_csk_accept() to __inet_accept(). Note that SCTP somehow allocates a new socket by sk_alloc() in sk->sk_prot->accept() and clones fields manually, instead of using sk_clone_lock(). mem_cgroup_sk_alloc() is called for SCTP before __inet_accept(), so I added the protocol check in __inet_accept(), but this can be removed once SCTP uses sk_clone_lock(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://patch.msgid.link/20251014235604.3057003-2-kuniyu@google.com
2025-10-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski3-20/+15
Cross-merge networking fixes after downstream PR (net-6.18-rc2). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-16udp: do not use skb_release_head_state() before skb_attempt_defer_free()Eric Dumazet1-2/+0
Michal reported and bisected an issue after recent adoption of skb_attempt_defer_free() in UDP. The issue here is that skb_release_head_state() is called twice per skb, one time from skb_consume_udp(), then a second time from skb_defer_free_flush() and napi_consume_skb(). As Sabrina suggested, remove skb_release_head_state() call from skb_consume_udp(). Add a DEBUG_NET_WARN_ON_ONCE(skb_nfct(skb)) in skb_attempt_defer_free() Many thanks to Michal, Sabrina, Paolo and Florian for their help. Fixes: 6471658dc66c ("udp: use skb_attempt_defer_free()") Reported-and-bisected-by: Michal Kubecek <mkubecek@suse.cz> Closes: https://lore.kernel.org/netdev/gpjh4lrotyephiqpuldtxxizrsg6job7cvhiqrw72saz2ubs3h@g6fgbvexgl3r/ Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Michal Kubecek <mkubecek@suse.cz> Cc: Sabrina Dubroca <sd@queasysnail.net> Cc: Florian Westphal <fw@strlen.de> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20251015052715.4140493-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-15tcp: better handle TCP_TX_DELAY on established flowsEric Dumazet2-6/+29
Some applications uses TCP_TX_DELAY socket option after TCP flow is established. Some metrics need to be updated, otherwise TCP might take time to adapt to the new (emulated) RTT. This patch adjusts tp->srtt_us, tp->rtt_min, icsk_rto and sk->sk_pacing_rate. This is best effort, and for instance icsk_rto is reset without taking backoff into account. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251013145926.833198-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-14tcp: fix tcp_tso_should_defer() vs large RTTEric Dumazet1-4/+15
Neal reported that using neper tcp_stream with TCP_TX_DELAY set to 50ms would often lead to flows stuck in a small cwnd mode, regardless of the congestion control. While tcp_stream sets TCP_TX_DELAY too late after the connect(), it highlighted two kernel bugs. The following heuristic in tcp_tso_should_defer() seems wrong for large RTT: delta = tp->tcp_clock_cache - head->tstamp; /* If next ACK is likely to come too late (half srtt), do not defer */ if ((s64)(delta - (u64)NSEC_PER_USEC * (tp->srtt_us >> 4)) < 0) goto send_now; If next ACK is expected to come in more than 1 ms, we should not defer because we prefer a smooth ACK clocking. While blamed commit was a step in the good direction, it was not generic enough. Another patch fixing TCP_TX_DELAY for established flows will be proposed when net-next reopens. Fixes: 50c8339e9299 ("tcp: tso: restore IW10 after TSO autosizing") Reported-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Tested-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251011115742.1245771-1-edumazet@google.com [pabeni@redhat.com: fixed whitespace issue] Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-10-13net/ip6_tunnel: Prevent perpetual tunnel growthDmitry Safonov1-14/+0
Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer. Fixes: 8eb30be0352d ("ipv6: Create ip6_tnl_xmit") Cc: Florian Westphal <fw@strlen.de> Cc: Francesco Ruggeri <fruggeri05@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://patch.msgid.link/20251009-ip6_tunnel-headroom-v2-1-8e4dbd8f7e35@arista.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-06tcp: take care of zero tp->window_clamp in tcp_set_rcvlowat()Eric Dumazet1-1/+4
Some applications (like selftests/net/tcp_mmap.c) call SO_RCVLOWAT on their listener, before accept(). This has an unfortunate effect on wscale selection in tcp_select_initial_window() during 3WHS. For instance, tcp_mmap was negotiating wscale 4, regardless of tcp_rmem[2] and sysctl_rmem_max. Do not change tp->window_clamp if it is zero or bigger than our computed value. Zero value is special, it allows tcp_select_initial_window() to enable autotuning. Note that SO_RCVLOWAT use on listener is probably not wise, because tp->scaling_ratio has a default value, possibly wrong. Fixes: d1361840f8c5 ("tcp: fix SO_RCVLOWAT and RCVBUF autotuning") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20251003184119.2526655-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-06tcp: Don't call reqsk_fastopen_remove() in tcp_conn_request().Kuniyuki Iwashima1-1/+0
syzbot reported the splat below in tcp_conn_request(). [0] If a listener is close()d while a TFO socket is being processed in tcp_conn_request(), inet_csk_reqsk_queue_add() does not set reqsk->sk and calls inet_child_forget(), which calls tcp_disconnect() for the TFO socket. After the cited commit, tcp_disconnect() calls reqsk_fastopen_remove(), where reqsk_put() is called due to !reqsk->sk. Then, reqsk_fastopen_remove() in tcp_conn_request() decrements the last req->rsk_refcnt and frees reqsk, and __reqsk_free() at the drop_and_free label causes the refcount underflow for the listener and double-free of the reqsk. Let's remove reqsk_fastopen_remove() in tcp_conn_request(). Note that other callers make sure tp->fastopen_rsk is not NULL. [0]: refcount_t: underflow; use-after-free. WARNING: CPU: 12 PID: 5563 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28) Modules linked in: CPU: 12 UID: 0 PID: 5563 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:refcount_warn_saturate (lib/refcount.c:28) Code: ab e8 8e b4 98 ff 0f 0b c3 cc cc cc cc cc 80 3d a4 e4 d6 01 00 75 9c c6 05 9b e4 d6 01 01 48 c7 c7 e8 df fb ab e8 6a b4 98 ff <0f> 0b e9 03 5b 76 00 cc 80 3d 7d e4 d6 01 00 0f 85 74 ff ff ff c6 RSP: 0018:ffffa79fc0304a98 EFLAGS: 00010246 RAX: d83af4db1c6b3900 RBX: ffff9f65c7a69020 RCX: d83af4db1c6b3900 RDX: 0000000000000000 RSI: 00000000ffff7fff RDI: ffffffffac78a280 RBP: 000000009d781b60 R08: 0000000000007fff R09: ffffffffac6ca280 R10: 0000000000017ffd R11: 0000000000000004 R12: ffff9f65c7b4f100 R13: ffff9f65c7d23c00 R14: ffff9f65c7d26000 R15: ffff9f65c7a64ef8 FS: 00007f9f962176c0(0000) GS:ffff9f65fcf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000180 CR3: 000000000dbbe006 CR4: 0000000000372ef0 Call Trace: <IRQ> tcp_conn_request (./include/linux/refcount.h:400 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/sock.h:1965 ./include/net/request_sock.h:131 net/ipv4/tcp_input.c:7301) tcp_rcv_state_process (net/ipv4/tcp_input.c:6708) tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1670) tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1906) ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:438) ip6_input (net/ipv6/ip6_input.c:500) ipv6_rcv (net/ipv6/ip6_input.c:311) __netif_receive_skb (net/core/dev.c:6104) process_backlog (net/core/dev.c:6456) __napi_poll (net/core/dev.c:7506) net_rx_action (net/core/dev.c:7569 net/core/dev.c:7696) handle_softirqs (kernel/softirq.c:579) do_softirq (kernel/softirq.c:480) </IRQ> Fixes: 45c8a6cc2bcd ("tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251001233755.1340927-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-03net: psp: don't assume reply skbs will have a socketJakub Kicinski1-1/+1
Rx path may be passing around unreferenced sockets, which means that skb_set_owner_edemux() may not set skb->sk and PSP will crash: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:psp_reply_set_decrypted (./include/net/psp/functions.h:132 net/psp/psp_sock.c:287) tcp_v6_send_response.constprop.0 (net/ipv6/tcp_ipv6.c:979) tcp_v6_send_reset (net/ipv6/tcp_ipv6.c:1140 (discriminator 1)) tcp_v6_do_rcv (net/ipv6/tcp_ipv6.c:1683) tcp_v6_rcv (net/ipv6/tcp_ipv6.c:1912) Fixes: 659a2899a57d ("tcp: add datapath logic for PSP with inline key exchange") Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251001022426.2592750-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-02Merge tag 'net-next-6.18' of ↵Linus Torvalds53-1167/+1752
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Paolo Abeni: "Core & protocols: - Improve drop account scalability on NUMA hosts for RAW and UDP sockets and the backlog, almost doubling the Pps capacity under DoS - Optimize the UDP RX performance under stress, reducing contention, revisiting the binary layout of the involved data structs and implementing NUMA-aware locking. This improves UDP RX performance by an additional 50%, even more under extreme conditions - Add support for PSP encryption of TCP connections; this mechanism has some similarities with IPsec and TLS, but offers superior HW offloads capabilities - Ongoing work to support Accurate ECN for TCP. AccECN allows more than one congestion notification signal per RTT and is a building block for Low Latency, Low Loss, and Scalable Throughput (L4S) - Reorganize the TCP socket binary layout for data locality, reducing the number of touched cachelines in the fastpath - Refactor skb deferral free to better scale on large multi-NUMA hosts, this improves TCP and UDP RX performances significantly on such HW - Increase the default socket memory buffer limits from 256K to 4M to better fit modern link speeds - Improve handling of setups with a large number of nexthop, making dump operating scaling linearly and avoiding unneeded synchronize_rcu() on delete - Improve bridge handling of VLAN FDB, storing a single entry per bridge instead of one entry per port; this makes the dump order of magnitude faster on large switches - Restore IP ID correctly for encapsulated packets at GSO segmentation time, allowing GRO to merge packets in more scenarios - Improve netfilter matching performance on large sets - Improve MPTCP receive path performance by leveraging recently introduced core infrastructure (skb deferral free) and adopting recent TCP autotuning changes - Allow bridges to redirect to a backup port when the bridge port is administratively down - Introduce MPTCP 'laminar' endpoint that con be used only once per connection and simplify common MPTCP setups - Add RCU safety to dst->dev, closing a lot of possible races - A significant crypto library API for SCTP, MPTCP and IPv6 SR, reducing code duplication - Supports pulling data from an skb frag into the linear area of an XDP buffer Things we sprinkled into general kernel code: - Generate netlink documentation from YAML using an integrated YAML parser Driver API: - Support using IPv6 Flow Label in Rx hash computation and RSS queue selection - Introduce API for fetching the DMA device for a given queue, allowing TCP zerocopy RX on more H/W setups - Make XDP helpers compatible with unreadable memory, allowing more easily building DevMem-enabled drivers with a unified XDP/skbs datapath - Add a new dedicated ethtool callback enabling drivers to provide the number of RX rings directly, improving efficiency and clarity in RX ring queries and RSS configuration - Introduce a burst period for the health reporter, allowing better handling of multiple errors due to the same root cause - Support for DPLL phase offset exponential moving average, controlling the average smoothing factor Device drivers: - Add a new Huawei driver for 3rd gen NIC (hinic3) - Add a new SpacemiT driver for K1 ethernet MAC - Add a generic abstraction for shared memory communication devices (dibps) - Ethernet high-speed NICs: - nVidia/Mellanox: - Use multiple per-queue doorbell, to avoid MMIO contention issues - support adjacent functions, allowing them to delegate their SR-IOV VFs to sibling PFs - support RSS for IPSec offload - support exposing raw cycle counters in PTP and mlx5 - support for disabling host PFs. - Intel (100G, ice, idpf): - ice: support for SRIOV VFs over an Active-Active link aggregate - ice: support for firmware logging via debugfs - ice: support for Earliest TxTime First (ETF) hardware offload - idpf: support basic XDP functionalities and XSk - Broadcom (bnxt): - support Hyper-V VF ID - dynamic SRIOV resource allocations for RoCE - Meta (fbnic): - support queue API, zero-copy Rx and Tx - support basic XDP functionalities - devlink health support for FW crashes and OTP mem corruptions - expand hardware stats coverage to FEC, PHY, and Pause - Wangxun: - support ethtool coalesce options - support for multiple RSS contexts - Ethernet virtual: - Macsec: - replace custom netlink attribute checks with policy-level checks - Bonding: - support aggregator selection based on port priority - Microsoft vNIC: - use page pool fragments for RX buffers instead of full pages to improve memory efficiency - Ethernet NICs consumer, and embedded: - Qualcomm: support Ethernet function for IPQ9574 SoC - Airoha: implement wlan offloading via NPU - Freescale - enetc: add NETC timer PTP driver and add PTP support - fec: enable the Jumbo frame support for i.MX8QM - Renesas (R-Car S4): - support HW offloading for layer 2 switching - support for RZ/{T2H, N2H} SoCs - Cadence (macb): support TAPRIO traffic scheduling - TI: - support for Gigabit ICSS ethernet SoC (icssm-prueth) - Synopsys (stmmac): a lot of cleanups - Ethernet PHYs: - Support 10g-qxgmi phy-mode for AQR412C, Felix DSA and Lynx PCS driver - Support bcm63268 GPHY power control - Support for Micrel lan8842 PHY and PTP - Support for Aquantia AQR412 and AQR115 - CAN: - a large CAN-XL preparation work - reorganize raw_sock and uniqframe struct to minimize memory usage - rcar_canfd: update the CAN-FD handling - WiFi: - extended Neighbor Awareness Networking (NAN) support - S1G channel representation cleanup - improve S1G support - WiFi drivers: - Intel (iwlwifi): - major refactor and cleanup - Broadcom (brcm80211): - support for AP isolation - RealTek (rtw88/89) rtw88/89: - preparation work for RTL8922DE support - MediaTek (mt76): - HW restart improvements - MLO support - Qualcomm/Atheros (ath10k): - GTK rekey fixes - Bluetooth drivers: - btusb: support for several new IDs for MT7925 - btintel: support for BlazarIW core - btintel_pcie: support for _suspend() / _resume() - btintel_pcie: support for Scorpious, Panther Lake-H484 IDs" * tag 'net-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1536 commits) net: stmmac: Add support for Allwinner A523 GMAC200 dt-bindings: net: sun8i-emac: Add A523 GMAC200 compatible Revert "Documentation: net: add flow control guide and document ethtool API" octeontx2-pf: fix bitmap leak octeontx2-vf: fix bitmap leak net/mlx5e: Use extack in set rxfh callback net/mlx5e: Introduce mlx5e_rss_params for RSS configuration net/mlx5e: Introduce mlx5e_rss_init_params net/mlx5e: Remove unused mdev param from RSS indir init net/mlx5: Improve QoS error messages with actual depth values net/mlx5e: Prevent entering switchdev mode with inconsistent netns net/mlx5: HWS, Generalize complex matchers net/mlx5: Improve write-combining test reliability for ARM64 Grace CPUs selftests/net: add tcp_port_share to .gitignore Revert "net/mlx5e: Update and set Xon/Xoff upon MTU set" net: add NUMA awareness to skb_attempt_defer_free() net: use llist for sd->defer_list net: make softnet_data.defer_count an atomic selftests: drv-net: psp: add tests for destroying devices selftests: drv-net: psp: add test for auto-adjusting TCP MSS ...
2025-09-29tcp: make tcp_rcvbuf_grow() accessible to mptcp codePaolo Abeni1-1/+1
To leverage the auto-tuning improvements brought by commit 2da35e4b4df9 ("Merge branch 'tcp-receive-side-improvements'"), the MPTCP stack need to access the mentioned helper. Acked-by: Geliang Tang <geliang@kernel.org> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250927-net-next-mptcp-rcv-path-imp-v1-2-5da266aa9c1a@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29tcp: use skb->len instead of skb->truesize in tcp_can_ingest()Eric Dumazet1-2/+13
Some applications are stuck to the 20th century and still use small SO_RCVBUF values. After the blamed commit, we can drop packets especially when using LRO/hw-gro enabled NIC and small MSS (1500) values. LRO/hw-gro NIC pack multiple segments into pages, allowing tp->scaling_ratio to be set to a high value. Whenever the receive queue gets full, we can receive a small packet filling RWIN, but with a high skb->truesize, because most NIC use 4K page plus sk_buff metadata even when receiving less than 1500 bytes of payload. Even if we refine how tp->scaling_ratio is estimated, we could have an issue at the start of the flow, because the first round of packets (IW10) will be sent based on the initial tp->scaling_ratio (1/2) Relax tcp_can_ingest() to use skb->len instead of skb->truesize, allowing the peer to use final RWIN, assuming a 'perfect' scaling_ratio of 1. Fixes: 1d2fbaad7cd8 ("tcp: stronger sk_rcvbuf checks") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250927092827.2707901-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-29Merge tag 'namespace-6.18-rc1' of ↵Linus Torvalds2-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull namespace updates from Christian Brauner: "This contains a larger set of changes around the generic namespace infrastructure of the kernel. Each specific namespace type (net, cgroup, mnt, ...) embedds a struct ns_common which carries the reference count of the namespace and so on. We open-coded and cargo-culted so many quirks for each namespace type that it just wasn't scalable anymore. So given there's a bunch of new changes coming in that area I've started cleaning all of this up. The core change is to make it possible to correctly initialize every namespace uniformly and derive the correct initialization settings from the type of the namespace such as namespace operations, namespace type and so on. This leaves the new ns_common_init() function with a single parameter which is the specific namespace type which derives the correct parameters statically. This also means the compiler will yell as soon as someone does something remotely fishy. The ns_common_init() addition also allows us to remove ns_alloc_inum() and drops any special-casing of the initial network namespace in the network namespace initialization code that Linus complained about. Another part is reworking the reference counting. The reference counting was open-coded and copy-pasted for each namespace type even though they all followed the same rules. This also removes all open accesses to the reference count and makes it private and only uses a very small set of dedicated helpers to manipulate them just like we do for e.g., files. In addition this generalizes the mount namespace iteration infrastructure introduced a few cycles ago. As reminder, the vfs makes it possible to iterate sequentially and bidirectionally through all mount namespaces on the system or all mount namespaces that the caller holds privilege over. This allow userspace to iterate over all mounts in all mount namespaces using the listmount() and statmount() system call. Each mount namespace has a unique identifier for the lifetime of the systems that is exposed to userspace. The network namespace also has a unique identifier working exactly the same way. This extends the concept to all other namespace types. The new nstree type makes it possible to lookup namespaces purely by their identifier and to walk the namespace list sequentially and bidirectionally for all namespace types, allowing userspace to iterate through all namespaces. Looking up namespaces in the namespace tree works completely locklessly. This also means we can move the mount namespace onto the generic infrastructure and remove a bunch of code and members from struct mnt_namespace itself. There's a bunch of stuff coming on top of this in the future but for now this uses the generic namespace tree to extend a concept introduced first for pidfs a few cycles ago. For a while now we have supported pidfs file handles for pidfds. This has proven to be very useful. This extends the concept to cover namespaces as well. It is possible to encode and decode namespace file handles using the common name_to_handle_at() and open_by_handle_at() apis. As with pidfs file handles, namespace file handles are exhaustive, meaning it is not required to actually hold a reference to nsfs in able to decode aka open_by_handle_at() a namespace file handle. Instead the FD_NSFS_ROOT constant can be passed which will let the kernel grab a reference to the root of nsfs internally and thus decode the file handle. Namespaces file descriptors can already be derived from pidfds which means they aren't subject to overmount protection bugs. IOW, it's irrelevant if the caller would not have access to an appropriate /proc/<pid>/ns/ directory as they could always just derive the namespace based on a pidfd already. It has the same advantage as pidfds. It's possible to reliably and for the lifetime of the system refer to a namespace without pinning any resources and to compare them trivially. Permission checking is kept simple. If the caller is located in the namespace the file handle refers to they are able to open it otherwise they must hold privilege over the owning namespace of the relevant namespace. The namespace file handle layout is exposed as uapi and has a stable and extensible format. For now it simply contains the namespace identifier, the namespace type, and the inode number. The stable format means that userspace may construct its own namespace file handles without going through name_to_handle_at() as they are already allowed for pidfs and cgroup file handles" * tag 'namespace-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (65 commits) ns: drop assert ns: move ns type into struct ns_common nstree: make struct ns_tree private ns: add ns_debug() ns: simplify ns_common_init() further cgroup: add missing ns_common include ns: use inode initializer for initial namespaces selftests/namespaces: verify initial namespace inode numbers ns: rename to __ns_ref nsfs: port to ns_ref_*() helpers net: port to ns_ref_*() helpers uts: port to ns_ref_*() helpers ipv4: use check_net() net: use check_net() net-sysfs: use check_net() user: port to ns_ref_*() helpers time: port to ns_ref_*() helpers pid: port to ns_ref_*() helpers ipc: port to ns_ref_*() helpers cgroup: port to ns_ref_*() helpers ...
2025-09-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+7
Cross-merge networking fixes after downstream PR (net-6.17-rc8). Conflicts: drivers/net/can/spi/hi311x.c 6b6968084721 ("can: hi311x: fix null pointer dereference when resuming from sleep before interface was enabled") 27ce71e1ce81 ("net: WQ_PERCPU added to alloc_workqueue users") https://lore.kernel.org/72ce7599-1b5b-464a-a5de-228ff9724701@kernel.org net/smc/smc_loopback.c drivers/dibs/dibs_loopback.c a35c04de2565 ("net/smc: fix warning in smc_rx_splice() when calling get_page()") cc21191b584c ("dibs: Move data path to dibs layer") https://lore.kernel.org/74368a5c-48ac-4f8e-a198-40ec1ed3cf5f@kernel.org Adjacent changes: drivers/net/dsa/lantiq/lantiq_gswip.c c0054b25e2f1 ("net: dsa: lantiq_gswip: move gswip_add_single_port_br() call to port_setup()") 7a1eaef0a791 ("net: dsa: lantiq_gswip: support model-specific mac_select_pcs()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-25net: gro: remove unnecessary df checksRichard Gobert1-3/+0
Currently, packets with fixed IDs will be merged only if their don't-fragment bit is set. This restriction is unnecessary since packets without the don't-fragment bit will be forwarded as-is even if they were merged together. The merged packets will be segmented into their original forms before being forwarded, either by GSO or by TSO. The IDs will also remain identical unless NETIF_F_TSO_MANGLEID is set, in which case the IDs can become incrementing, which is also fine. Clean up the code by removing the unnecessary don't-fragment checks. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-5-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-25net: gso: restore ids of outer ip headers correctlyRichard Gobert2-11/+8
Currently, NETIF_F_TSO_MANGLEID indicates that the inner-most ID can be mangled. Outer IDs can always be mangled. Make GSO preserve outer IDs by default, with NETIF_F_TSO_MANGLEID allowing both inner and outer IDs to be mangled. This commit also modifies a few drivers that use SKB_GSO_FIXEDID directly. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> # for sfc Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-4-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-25net: gro: only merge packets with incrementing or fixed outer idsRichard Gobert1-1/+4
Only merge encapsulated packets if their outer IDs are either incrementing or fixed, just like for inner IDs and IDs of non-encapsulated packets. Add another ip_fixedid bit for a total of two bits: one for outer IDs (and for unencapsulated packets) and one for inner IDs. This commit preserves the current behavior of GSO where only the IDs of the inner-most headers are restored correctly. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-3-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-25net: gro: remove is_ipv6 from napi_gro_cbRichard Gobert2-20/+14
Remove is_ipv6 from napi_gro_cb and use sk->sk_family instead. This frees up space for another ip_fixedid bit that will be added in the next commit. udp_sock_create always creates either a AF_INET or a AF_INET6 socket, so using sk->sk_family is reliable. In IPv6-FOU, cfg->ipv6_v6only is always enabled. Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250923085908.4687-2-richardbgobert@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-23nexthop: Forbid FDB status change while nexthop is in a groupIdo Schimmel1-0/+7
The kernel forbids the creation of non-FDB nexthop groups with FDB nexthops: # ip nexthop add id 1 via 192.0.2.1 fdb # ip nexthop add id 2 group 1 Error: Non FDB nexthop group cannot have fdb nexthops. And vice versa: # ip nexthop add id 3 via 192.0.2.2 dev dummy1 # ip nexthop add id 4 group 3 fdb Error: FDB nexthop group can only have fdb nexthops. However, as long as no routes are pointing to a non-FDB nexthop group, the kernel allows changing the type of a nexthop from FDB to non-FDB and vice versa: # ip nexthop add id 5 via 192.0.2.2 dev dummy1 # ip nexthop add id 6 group 5 # ip nexthop replace id 5 via 192.0.2.2 fdb # echo $? 0 This configuration is invalid and can result in a NPD [1] since FDB nexthops are not associated with a nexthop device: # ip route add 198.51.100.1/32 nhid 6 # ping 198.51.100.1 Fix by preventing nexthop FDB status change while the nexthop is in a group: # ip nexthop add id 7 via 192.0.2.2 dev dummy1 # ip nexthop add id 8 group 7 # ip nexthop replace id 7 via 192.0.2.2 fdb Error: Cannot change nexthop FDB status while in a group. [1] BUG: kernel NULL pointer dereference, address: 00000000000003c0 [...] Oops: Oops: 0000 [#1] SMP CPU: 6 UID: 0 PID: 367 Comm: ping Not tainted 6.17.0-rc6-virtme-gb65678cacc03 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 RIP: 0010:fib_lookup_good_nhc+0x1e/0x80 [...] Call Trace: <TASK> fib_table_lookup+0x541/0x650 ip_route_output_key_hash_rcu+0x2ea/0x970 ip_route_output_key_hash+0x55/0x80 __ip4_datagram_connect+0x250/0x330 udp_connect+0x2b/0x60 __sys_connect+0x9c/0xd0 __x64_sys_connect+0x18/0x20 do_syscall_64+0xa4/0x2a0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Fixes: 38428d68719c ("nexthop: support for fdb ecmp nexthops") Reported-by: syzbot+6596516dd2b635ba2350@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68c9a4d2.050a0220.3c6139.0e63.GAE@google.com/ Tested-by: syzbot+6596516dd2b635ba2350@syzkaller.appspotmail.com Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250921150824.149157-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-23udp: remove busylock and add per NUMA queuesEric Dumazet1-46/+71
busylock was protecting UDP sockets against packet floods, but unfortunately was not protecting the host itself. Under stress, many cpus could spin while acquiring the busylock, and NIC had to drop packets. Or packets would be dropped in cpu backlog if RPS/RFS were in place. This patch replaces the busylock by intermediate lockless queues. (One queue per NUMA node). This means that fewer number of cpus have to acquire the UDP receive queue lock. Most of the cpus can either: - immediately drop the packet. - or queue it in their NUMA aware lockless queue. Then one of the cpu is chosen to process this lockless queue in a batch. The batch only contains packets that were cooked on the same NUMA node, thus with very limited latency impact. Tested: DDOS targeting a victim UDP socket, on a platform with 6 NUMA nodes (Intel(R) Xeon(R) 6985P-C) Before: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 1004179 0.0 Udp6InErrors 3117 0.0 Udp6RcvbufErrors 3117 0.0 After: nstat -n ; sleep 1 ; nstat | grep Udp Udp6InDatagrams 1116633 0.0 Udp6InErrors 14197275 0.0 Udp6RcvbufErrors 14197275 0.0 We can see this host can now proces 14.2 M more packets per second while under attack, and the victim socket can receive 11 % more packets. I used a small bpftrace program measuring time (in us) spent in __udp_enqueue_schedule_skb(). Before: @udp_enqueue_us[398]: [0] 24901 |@@@ | [1] 63512 |@@@@@@@@@ | [2, 4) 344827 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [4, 8) 244673 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [8, 16) 54022 |@@@@@@@@ | [16, 32) 222134 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [32, 64) 232042 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [64, 128) 4219 | | [128, 256) 188 | | After: @udp_enqueue_us[398]: [0] 5608855 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [1] 1111277 |@@@@@@@@@@ | [2, 4) 501439 |@@@@ | [4, 8) 102921 | | [8, 16) 29895 | | [16, 32) 43500 | | [32, 64) 31552 | | [64, 128) 979 | | [128, 256) 13 | | Note that the remaining bottleneck for this platform is in udp_drops_inc() because we limited struct numa_drop_counters to only two nodes so far. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250922104240.2182559-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-23tcp: Update bind bucket state on port releaseJakub Sitnicki3-5/+52
Today, once an inet_bind_bucket enters a state where fastreuse >= 0 or fastreuseport >= 0 after a socket is explicitly bound to a port, it remains in that state until all sockets are removed and the bucket is destroyed. In this state, the bucket is skipped during ephemeral port selection in connect(). For applications using a reduced ephemeral port range (IP_LOCAL_PORT_RANGE socket option), this can cause faster port exhaustion since blocked buckets are excluded from reuse. The reason the bucket state isn't updated on port release is unclear. Possibly a performance trade-off to avoid scanning bucket owners, or just an oversight. Fix it by recalculating the bucket state when a socket releases a port. To limit overhead, each inet_bind2_bucket stores its own (fastreuse, fastreuseport) state. On port release, only the relevant port-addr bucket is scanned, and the overall state is derived from these. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250917-update-bind-bucket-state-on-unhash-v5-1-57168b661b47@cloudflare.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-22tcp: reclaim 8 bytes in struct request_sock_queueEric Dumazet1-2/+2
synflood_warned had to be u32 for xchg(), but ensuring atomicity is not really needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: move tcp_clean_acked to tcp_sock_read_tx groupEric Dumazet1-3/+3
tp->tcp_clean_acked is fetched in tx path when snd_una is updated. This field thus belongs to tcp_sock_read_tx group. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: move tcp->rcv_tstamp to tcp_sock_write_txrx groupEric Dumazet1-1/+1
tcp_ack() writes this field, it belongs to tcp_sock_write_txrx. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: remove CACHELINE_ASSERT_GROUP_SIZE() usesEric Dumazet1-12/+0
Maintaining the CACHELINE_ASSERT_GROUP_SIZE() uses for struct tcp_sock has been painful. This had little benefit, so remove them. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22net: move sk->sk_err_soft and sk->sk_sndbufEric Dumazet1-1/+2
sk->sk_sndbuf is read-mostly in tx path, so move it from sock_write_tx group to more appropriate sock_read_tx. sk->sk_err_soft was not identified previously, but is used from tcp_ack(). Move it to sock_write_tx group for better cache locality. Also change tcp_ack() to clear sk->sk_err_soft only if needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250919204856.2977245-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22net: replace use of system_wq with system_percpu_wqMarco Crivellari1-1/+1
Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. system_unbound_wq should be the default workqueue so as not to enforce locality constraints for random work whenever it's not required. Adding system_dfl_wq to encourage its use when unbound work should be used. The old system_unbound_wq will be kept for a few release cycles. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com> Link: https://patch.msgid.link/20250918142427.309519-3-marco.crivellari@suse.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: Remove redundant sk_unhashed() in inet_unhash().Kuniyuki Iwashima1-9/+0
inet_unhash() checks sk_unhashed() twice at the entry and after locking ehash/lhash bucket. The former was somehow added redundantly by commit 4f9bf2a2f5aa ("tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH."). inet_unhash() is called for the full socket from 4 places, and it is always under lock_sock() or the socket is not yet published to other threads: 1. __sk_prot_rehash() -> called from inet_sk_reselect_saddr(), which has lockdep_sock_is_held() 2. sk_common_release() -> called when inet_create() or inet6_create() fail, then the socket is not yet published 3. tcp_set_state() -> calls tcp_call_bpf_2arg(), and tcp_call_bpf() has sock_owned_by_me() 4. inet_ctl_sock_create() -> creates a kernel socket and unhashes it immediately, but TCP socket is not hashed in sock_create_kern() (only SOCK_RAW is) So we do not need to check sk_unhashed() twice before/after ehash/lhash lock in inet_unhash(). Let's remove the 2nd one. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250919083706.1863217-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: Remove inet6_hash().Kuniyuki Iwashima1-12/+5
inet_hash() and inet6_hash() are exactly the same. Also, we do not need to export inet6_hash(). Let's consolidate the two into __inet_hash() and rename it to inet_hash(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250919083706.1863217-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-22tcp: Remove osk from __inet_hash() arg.Kuniyuki Iwashima1-3/+3
__inet_hash() is called from inet_hash() and inet6_hash with osk NULL. Let's remove the 2nd arg from __inet_hash(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250919083706.1863217-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19net: ipv4: convert ip_rcv_options to drop reasonsAntoine Tenart1-12/+12
This converts the only path not returning drop reasons in ip_rcv_finish_core. Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250915091958.15382-4-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19net: ipv4: simplify drop reason handling in ip_rcv_finish_coreAntoine Tenart1-4/+3
Instead of setting the drop reason to SKB_DROP_REASON_NOT_SPECIFIED early and having to reset it each time it is overridden by a function returned value, just set the drop reason to the expected value before returning from ip_rcv_finish_core. Signed-off-by: Antoine Tenart <atenart@kernel.org> Link: https://patch.msgid.link/20250915091958.15382-3-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19net: ipv4: make udp_v4_early_demux explicitly return drop reasonAntoine Tenart2-7/+7
udp_v4_early_demux already returns drop reasons as it either returns 0 or ip_mc_validate_source, which itself returns drop reasons. Its return value is also already used as a drop reason itself. Makes this explicit by making it return drop reasons. Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250915091958.15382-2-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19tcp: prefer sk_skb_reason_drop()Eric Dumazet1-1/+1
Replace two calls to kfree_skb_reason() with sk_skb_reason_drop(). Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250918132007.325299-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-19ipv4: use check_net()Christian Brauner2-3/+3
Don't directly acess the namespace count. There's even a dedicated helper for this. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-1/+8
Cross-merge networking fixes after downstream PR (net-6.17-rc7). No conflicts. Adjacent changes: drivers/net/ethernet/mellanox/mlx5/core/en/fs.h 9536fbe10c9d ("net/mlx5e: Add PSP steering in local NIC RX") 7601a0a46216 ("net/mlx5e: Add a miss level for ipsec crypto offload") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-18Merge branch 'add-basic-psp-encryption-for-tcp-connections'Paolo Abeni7-10/+59
Daniel Zahka says: ================== add basic PSP encryption for TCP connections This is v13 of the PSP RFC [1] posted by Jakub Kicinski one year ago. General developments since v1 include a fork of packetdrill [2] with support for PSP added, as well as some test cases, and an implementation of PSP key exchange and connection upgrade [3] integrated into the fbthrift RPC library. Both [2] and [3] have been tested on server platforms with PSP-capable CX7 NICs. Below is the cover letter from the original RFC: Add support for PSP encryption of TCP connections. PSP is a protocol out of Google: https://github.com/google/psp/blob/main/doc/PSP_Arch_Spec.pdf which shares some similarities with IPsec. I added some more info in the first patch so I'll keep it short here. The protocol can work in multiple modes including tunneling. But I'm mostly interested in using it as TLS replacement because of its superior offload characteristics. So this patch does three things: - it adds "core" PSP code PSP is offload-centric, and requires some additional care and feeding, so first chunk of the code exposes device info. This part can be reused by PSP implementations in xfrm, tunneling etc. - TCP integration TLS style Reuse some of the existing concepts from TLS offload, such as attaching crypto state to a socket, marking skbs as "decrypted", egress validation. PSP does not prescribe key exchange protocols. To use PSP as a more efficient TLS offload we intend to perform a TLS handshake ("inline" in the same TCP connection) and negotiate switching to PSP based on capabilities of both endpoints. This is also why I'm not including a software implementation. Nobody would use it in production, software TLS is faster, it has larger crypto records. - mlx5 implementation That's mostly other people's work, not 100% sure those folks consider it ready hence the RFC in the title. But it works :) Not posted, queued a branch [4] are follow up pieces: - standard stats - netdevsim implementation and tests [1] https://lore.kernel.org/netdev/20240510030435.120935-1-kuba@kernel.org/ [2] https://github.com/danieldzahka/packetdrill [3] https://github.com/danieldzahka/fbthrift/tree/dzahka/psp [4] https://github.com/kuba-moo/linux/tree/psp Comments we intend to defer to future series: - we prefer to keep the version field in the tx-assoc netlink request, because it makes parsing keys require less state early on, but we are willing to change in the next version of this series. - using a static branch to wrap psp_enqueue_set_decrypted() and other functions called from tcp. - using INDIRECT_CALL for tls/psp in sk_validate_xmit_skb(). We prefer to address this in a dedicated patch series, so that this series does not need to modify the way tls_validate_xmit_skb() is declared and stubbed out. v12: https://lore.kernel.org/netdev/20250916000559.1320151-1-kuba@kernel.org/ v11: https://lore.kernel.org/20250911014735.118695-1-daniel.zahka@gmail.com v10: https://lore.kernel.org/netdev/20250828162953.2707727-1-daniel.zahka@gmail.com/ v9: https://lore.kernel.org/netdev/20250827155340.2738246-1-daniel.zahka@gmail.com/ v8: https://lore.kernel.org/netdev/20250825200112.1750547-1-daniel.zahka@gmail.com/ v7: https://lore.kernel.org/netdev/20250820113120.992829-1-daniel.zahka@gmail.com/ v6: https://lore.kernel.org/netdev/20250812003009.2455540-1-daniel.zahka@gmail.com/ v5: https://lore.kernel.org/netdev/20250723203454.519540-1-daniel.zahka@gmail.com/ v4: https://lore.kernel.org/netdev/20250716144551.3646755-1-daniel.zahka@gmail.com/ v3: https://lore.kernel.org/netdev/20250702171326.3265825-1-daniel.zahka@gmail.com/ v2: https://lore.kernel.org/netdev/20250625135210.2975231-1-daniel.zahka@gmail.com/ v1: https://lore.kernel.org/netdev/20240510030435.120935-1-kuba@kernel.org/ ================== Links: https://patch.msgid.link/20250917000954.859376-1-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- * add-basic-psp-encryption-for-tcp-connections: net/mlx5e: Implement PSP key_rotate operation net/mlx5e: Add Rx data path offload psp: provide decapsulation and receive helper for drivers net/mlx5e: Configure PSP Rx flow steering rules net/mlx5e: Add PSP steering in local NIC RX net/mlx5e: Implement PSP Tx data path psp: provide encapsulation helper for drivers net/mlx5e: Implement PSP operations .assoc_add and .assoc_del net/mlx5e: Support PSP offload functionality psp: track generations of device key net: psp: update the TCP MSS to reflect PSP packet overhead net: psp: add socket security association code net: tcp: allow tcp_timewait_sock to validate skbs before handing to device net: move sk_validate_xmit_skb() to net/core/dev.c psp: add op for rotation of device key tcp: add datapath logic for PSP with inline key exchange net: modify core data structures for PSP datapath support psp: base PSP device support psp: add documentation
2025-09-18net: psp: update the TCP MSS to reflect PSP packet overheadJakub Kicinski1-2/+2
PSP eats 40B of header space. Adjust MSS appropriately. We can either modify tcp_mtu_to_mss() / tcp_mss_to_mtu() or reuse icsk_ext_hdr_len. The former option is more TCP specific and has runtime overhead. The latter is a bit of a hack as PSP is not an ext_hdr. If one squints hard enough, UDP encap is just a more practical version of IPv6 exthdr, so go with the latter. Happy to change. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-10-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18net: tcp: allow tcp_timewait_sock to validate skbs before handing to deviceDaniel Zahka1-0/+3
Provide a callback to validate skb's originating from tcp timewait socks before passing to the device layer. Full socks have a sk_validate_xmit_skb member for checking that a device is capable of performing offloads required for transmitting an skb. With psp, tcp timewait socks will inherit the crypto state from their corresponding full socks. Any ACKs or RSTs that originate from a tcp timewait sock carrying psp state should be psp encapsulated. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-8-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: add datapath logic for PSP with inline key exchangeJakub Kicinski6-8/+50
Add validation points and state propagation to support PSP key exchange inline, on TCP connections. The expectation is that application will use some well established mechanism like TLS handshake to establish a secure channel over the connection and if both endpoints are PSP-capable - exchange and install PSP keys. Because the connection can existing in PSP-unsecured and PSP-secured state we need to make sure that there are no race conditions or retransmission leaks. On Tx - mark packets with the skb->decrypted bit when PSP key is at the enqueue time. Drivers should only encrypt packets with this bit set. This prevents retransmissions getting encrypted when original transmission was not. Similarly to TLS, we'll use sk->sk_validate_xmit_skb to make sure PSP skbs can't "escape" via a PSP-unaware device without being encrypted. On Rx - validation is done under socket lock. This moves the validation point later than xfrm, for example. Please see the documentation patch for more details on the flow of securing a connection, but for the purpose of this patch what's important is that we want to enforce the invariant that once connection is secured any skb in the receive queue has been encrypted with PSP. Add GRO and coalescing checks to prevent PSP authenticated data from being combined with cleartext data, or data with non-matching PSP state. On Rx, check skb's with psp_skb_coalesce_diff() at points before psp_sk_rx_policy_check(). After skb's are policy checked and on the socket receive queue, skb_cmp_decrypted() is sufficient for checking for coalescable PSP state. On Tx, tcp_write_collapse_fence() should be called when transitioning a socket into PSP Tx state to prevent data sent as cleartext from being coalesced with PSP encapsulated data. This change only adds the validation points, for ease of review. Subsequent change will add the ability to install keys, and flesh the enforcement logic out Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-5-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18net: modify core data structures for PSP datapath supportJakub Kicinski2-0/+4
Add pointers to psp data structures to core networking structs, and an SKB extension to carry the PSP information from the drivers to the socket layer. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-4-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: use skb_attempt_defer_free()Eric Dumazet1-0/+7
Move skb freeing from udp recvmsg() path to the cpu which allocated/received it, as TCP did in linux-5.17. This increases max thoughput by 20% to 30%, depending on number of BH producers. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250916160951.541279-11-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: make busylock per socketEric Dumazet1-18/+2
While having all spinlocks packed into an array was a space saver, this also caused NUMA imbalance and hash collisions. UDPv6 socket size becomes 1600 after this patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250916160951.541279-10-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: add udp_drops_inc() helperEric Dumazet1-6/+6
Generic sk_drops_inc() reads sk->sk_drop_counters. We know the precise location for UDP sockets. Move sk_drop_counters out of sock_read_rxtx so that sock_write_rxtx starts at a cache line boundary. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250916160951.541279-9-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: update sk_rmem_alloc before busylock acquisitionEric Dumazet1-2/+5
Avoid piling too many producers on the busylock by updating sk_rmem_alloc before busylock acquisition. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250916160951.541279-7-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18udp: refine __udp_enqueue_schedule_skb() testEric Dumazet1-2/+2
Commit 5a465a0da13e ("udp: Fix multiple wraparounds of sk->sk_rmem_alloc.") allowed to slightly overshoot sk->sk_rmem_alloc, when many cpus are trying to feed packets to a common UDP socket. This patch, combined with the following one reduces false sharing on the victim socket under DDOS. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250916160951.541279-6-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: try to fit AccECN option with SACKChia-Yu Chang1-1/+20
As SACK blocks tend to eat all option space when there are many holes, it is useful to compromise on sending many SACK blocks in every ACK and attempt to fit the AccECN option there by reducing the number of SACK blocks. However, it will never go below two SACK blocks because of the AccECN option. As the AccECN option is often not put to every ACK, the space hijack is usually only temporary. Depending on the reuqired AccECN fields (can be either 3, 2, 1, or 0, cf. Table 5 in AccECN spec) and the NOPs used for alignment of other TCP options, up to two SACK blocks will be reduced. Please find below tables for more details: +====================+=========================================+ | Number of | Required | Remaining | Number of | Final | | SACK | AccECN | option | reduced | number of | | blocks | fields | spaces | SACK blocks | SACK blocks | +===========+==========+===========+=============+=============+ | x (<=2) | 0 to 3 | any | 0 | x | +-----------+----------+-----------+-------------+-------------+ | 3 | 0 | any | 0 | 3 | | 3 | 1 | <4 | 1 | 2 | | 3 | 1 | >=4 | 0 | 3 | | 3 | 2 | <8 | 1 | 2 | | 3 | 2 | >=8 | 0 | 3 | | 3 | 3 | <12 | 1 | 2 | | 3 | 3 | >=12 | 0 | 3 | +-----------+----------+-----------+-------------+-------------+ | y (>=4) | 0 | any | 0 | y | | y (>=4) | 1 | <4 | 1 | y-1 | | y (>=4) | 1 | >=4 | 0 | y | | y (>=4) | 2 | <8 | 1 | y-1 | | y (>=4) | 2 | >=8 | 0 | y | | y (>=4) | 3 | <4 | 2 | y-2 | | y (>=4) | 3 | <12 | 1 | y-1 | | y (>=4) | 3 | >=12 | 0 | y | +===========+==========+===========+=============+=============+ Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Co-developed-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Ilpo Järvinen <ij@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-11-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: AccECN option ceb/cep and ACE field multi-wrap heuristicsIlpo Järvinen1-2/+34
The AccECN option ceb/cep heuristic algorithm is from AccECN spec Appendix A.2.2 to mitigate against false ACE field overflows. Armed with ceb delta from option, delivered bytes, and delivered packets it is possible to estimate how many times ACE field wrapped. This calculation is necessary only if more than one wrap is possible. Without SACK, delivered bytes and packets are not always trustworthy in which case TCP falls back to the simpler no-or-all wraps ceb algorithm. Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-10-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: AccECN option failure handlingChia-Yu Chang4-5/+58
AccECN option may fail in various way, handle these: - Attempt to negotiate the use of AccECN on the 1st retransmitted SYN - From the 2nd retransmitted SYN, stop AccECN negotiation - Remove option from SYN/ACK rexmits to handle blackholes - If no option arrives in SYN/ACK, assume Option is not usable - If an option arrives later, re-enabled - If option is zeroed, disable AccECN option processing This patch use existing padding bits in tcp_request_sock and holes in tcp_sock without increasing the size. Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-9-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: AccECN option send controlChia-Yu Chang6-8/+39
Instead of sending the option in every ACK, limit sending to those ACKs where the option is necessary: - Handshake - "Change-triggered ACK" + the ACK following it. The 2nd ACK is necessary to unambiguously indicate which of the ECN byte counters in increasing. The first ACK has two counters increasing due to the ecnfield edge. - ACKs with CE to allow CEP delta validations to take advantage of the option. - Force option to be sent every at least once per 2^22 bytes. The check is done using the bit edges of the byte counters (avoids need for extra variables). - AccECN option beacon to send a few times per RTT even if nothing in the ECN state requires that. The default is 3 times per RTT, and its period can be set via sysctl_tcp_ecn_option_beacon. Below are the pahole outcomes before and after this patch, in which the group size of tcp_sock_write_tx is increased from 89 to 97 due to the new u64 accecn_opt_tstamp member: [BEFORE THIS PATCH] struct tcp_sock { [...] u64 tcp_wstamp_ns; /* 2488 8 */ struct list_head tsorted_sent_queue; /* 2496 16 */ [...] __cacheline_group_end__tcp_sock_write_tx[0]; /* 2521 0 */ __cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2521 0 */ u8 nonagle:4; /* 2521: 0 1 */ u8 rate_app_limited:1; /* 2521: 4 1 */ /* XXX 3 bits hole, try to pack */ /* Force alignment to the next boundary: */ u8 :0; u8 received_ce_pending:4;/* 2522: 0 1 */ u8 unused2:4; /* 2522: 4 1 */ u8 accecn_minlen:2; /* 2523: 0 1 */ u8 est_ecnfield:2; /* 2523: 2 1 */ u8 unused3:4; /* 2523: 4 1 */ [...] __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2628 0 */ [...] /* size: 3200, cachelines: 50, members: 171 */ } [AFTER THIS PATCH] struct tcp_sock { [...] u64 tcp_wstamp_ns; /* 2488 8 */ u64 accecn_opt_tstamp; /* 2596 8 */ struct list_head tsorted_sent_queue; /* 2504 16 */ [...] __cacheline_group_end__tcp_sock_write_tx[0]; /* 2529 0 */ __cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2529 0 */ u8 nonagle:4; /* 2529: 0 1 */ u8 rate_app_limited:1; /* 2529: 4 1 */ /* XXX 3 bits hole, try to pack */ /* Force alignment to the next boundary: */ u8 :0; u8 received_ce_pending:4;/* 2530: 0 1 */ u8 unused2:4; /* 2530: 4 1 */ u8 accecn_minlen:2; /* 2531: 0 1 */ u8 est_ecnfield:2; /* 2531: 2 1 */ u8 accecn_opt_demand:2; /* 2531: 4 1 */ u8 prev_ecnfield:2; /* 2531: 6 1 */ [...] __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2636 0 */ [...] /* size: 3200, cachelines: 50, members: 173 */ } Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Co-developed-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Ilpo Järvinen <ij@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-8-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: AccECN optionIlpo Järvinen5-10/+274
The Accurate ECN allows echoing back the sum of bytes for each IP ECN field value in the received packets using AccECN option. This change implements AccECN option tx & rx side processing without option send control related features that are added by a later change. Based on specification: https://tools.ietf.org/id/draft-ietf-tcpm-accurate-ecn-28.txt (Some features of the spec will be added in the later changes rather than in this one). A full-length AccECN option is always attempted but if it does not fit, the minimum length is selected based on the counters that have changed since the last update. The AccECN option (with 24-bit fields) often ends in odd sizes so the option write code tries to take advantage of some nop used to pad the other TCP options. The delivered_ecn_bytes pairs with received_ecn_bytes similar to how delivered_ce pairs with received_ce. In contrast to ACE field, however, the option is not always available to update delivered_ecn_bytes. For ACK w/o AccECN option, the delivered bytes calculated based on the cumulative ACK+SACK information are assigned to one of the counters using an estimation heuristic to select the most likely ECN byte counter. Any estimation error is corrected when the next AccECN option arrives. It may occur that the heuristic gets too confused when there are enough different byte counter deltas between ACKs with the AccECN option in which case the heuristic just gives up on updating the counters for a while. tcp_ecn_option sysctl can be used to select option sending mode for AccECN: TCP_ECN_OPTION_DISABLED, TCP_ECN_OPTION_MINIMUM, and TCP_ECN_OPTION_FULL. This patch increases the size of tcp_info struct, as there is no existing holes for new u32 variables. Below are the pahole outcomes before and after this patch: [BEFORE THIS PATCH] struct tcp_info { [...] __u32 tcpi_total_rto_time; /* 244 4 */ /* size: 248, cachelines: 4, members: 61 */ } [AFTER THIS PATCH] struct tcp_info { [...] __u32 tcpi_total_rto_time; /* 244 4 */ __u32 tcpi_received_ce; /* 248 4 */ __u32 tcpi_delivered_e1_bytes; /* 252 4 */ __u32 tcpi_delivered_e0_bytes; /* 256 4 */ __u32 tcpi_delivered_ce_bytes; /* 260 4 */ __u32 tcpi_received_e1_bytes; /* 264 4 */ __u32 tcpi_received_e0_bytes; /* 268 4 */ __u32 tcpi_received_ce_bytes; /* 272 4 */ /* size: 280, cachelines: 5, members: 68 */ } This patch uses the existing 1-byte holes in the tcp_sock_write_txrx group for new u8 members, but adds a 4-byte hole in tcp_sock_write_rx group after the new u32 delivered_ecn_bytes[3] member. Therefore, the group size of tcp_sock_write_rx is increased from 96 to 112. Below are the pahole outcomes before and after this patch: [BEFORE THIS PATCH] struct tcp_sock { [...] u8 received_ce_pending:4; /* 2522: 0 1 */ u8 unused2:4; /* 2522: 4 1 */ /* XXX 1 byte hole, try to pack */ [...] u32 rcv_rtt_last_tsecr; /* 2668 4 */ [...] __cacheline_group_end__tcp_sock_write_rx[0]; /* 2728 0 */ [...] /* size: 3200, cachelines: 50, members: 167 */ } [AFTER THIS PATCH] struct tcp_sock { [...] u8 received_ce_pending:4;/* 2522: 0 1 */ u8 unused2:4; /* 2522: 4 1 */ u8 accecn_minlen:2; /* 2523: 0 1 */ u8 est_ecnfield:2; /* 2523: 2 1 */ u8 unused3:4; /* 2523: 4 1 */ [...] u32 rcv_rtt_last_tsecr; /* 2668 4 */ u32 delivered_ecn_bytes[3];/* 2672 12 */ /* XXX 4 bytes hole, try to pack */ [...] __cacheline_group_end__tcp_sock_write_rx[0]; /* 2744 0 */ [...] /* size: 3200, cachelines: 50, members: 171 */ } Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Neal Cardwell <ncardwell@google.com> Co-developed-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-7-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: sack option handling improvementsIlpo Järvinen1-11/+14
1) Don't early return when sack doesn't fit. AccECN code will be placed after this fragment so no early returns please. 2) Make sure opts->num_sack_blocks is not left undefined. E.g., tcp_current_mss() does not memset its opts struct to zero. AccECN code checks if SACK option is present and may even alter it to make room for AccECN option when many SACK blocks are present. Thus, num_sack_blocks needs to be always valid. Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-6-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: AccECN needs to know delivered bytesIlpo Järvinen1-2/+12
AccECN byte counter estimation requires delivered bytes which can be calculated while processing SACK blocks and cumulative ACK. The delivered bytes will be used to estimate the byte counters between AccECN option (on ACKs w/o the option). Accurate ECN does not depend on SACK to function; however, the calculation would be more accurate if SACK were there. Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-5-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: add AccECN rx byte countersIlpo Järvinen3-5/+7
These three byte counters track IP ECN field payload byte sums for all arriving (acceptable) packets for ECT0, ECT1, and CE. The AccECN option (added by a later patch in the series) echoes these counters back to sender side; therefore, it is placed within the group of tcp_sock_write_txrx. Below are the pahole outcomes before and after this patch, in which the group size of tcp_sock_write_txrx is increased from 95 + 4 to 107 + 4 and an extra 4-byte hole is created but will be exploited in later patches: [BEFORE THIS PATCH] struct tcp_sock { [...] u32 delivered_ce; /* 2576 4 */ u32 received_ce; /* 2580 4 */ u32 app_limited; /* 2584 4 */ u32 rcv_wnd; /* 2588 4 */ struct tcp_options_received rx_opt; /* 2592 24 */ __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2616 0 */ [...] /* size: 3200, cachelines: 50, members: 166 */ } [AFTER THIS PATCH] struct tcp_sock { [...] u32 delivered_ce; /* 2576 4 */ u32 received_ce; /* 2580 4 */ u32 received_ecn_bytes[3];/* 2584 12 */ u32 app_limited; /* 2596 4 */ u32 rcv_wnd; /* 2600 4 */ struct tcp_options_received rx_opt; /* 2604 24 */ __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2628 0 */ /* XXX 4 bytes hole, try to pack */ [...] /* size: 3200, cachelines: 50, members: 167 */ } Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Neal Cardwell <ncardwell@google.com> Co-developed-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-4-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: accecn: AccECN negotiationIlpo Järvinen7-22/+76
Accurate ECN negotiation parts based on the specification: https://tools.ietf.org/id/draft-ietf-tcpm-accurate-ecn-28.txt Accurate ECN is negotiated using ECE, CWR and AE flags in the TCP header. TCP falls back into using RFC3168 ECN if one of the ends supports only RFC3168-style ECN. The AccECN negotiation includes reflecting IP ECN field value seen in SYN and SYNACK back using the same bits as negotiation to allow responding to SYN CE marks and to detect ECN field mangling. CE marks should not occur currently because SYN=1 segments are sent with Non-ECT in IP ECN field (but proposal exists to remove this restriction). Reflecting SYN IP ECN field in SYNACK is relatively simple. Reflecting SYNACK IP ECN field in the final/third ACK of the handshake is more challenging. Linux TCP code is not well prepared for using the final/third ACK a signalling channel which makes things somewhat complicated here. tcp_ecn sysctl can be used to select the highest ECN variant (Accurate ECN, ECN, No ECN) that is attemped to be negotiated and requested for incoming connection and outgoing connection: TCP_ECN_IN_NOECN_OUT_NOECN, TCP_ECN_IN_ECN_OUT_ECN, TCP_ECN_IN_ECN_OUT_NOECN, TCP_ECN_IN_ACCECN_OUT_ACCECN, TCP_ECN_IN_ACCECN_OUT_ECN, and TCP_ECN_IN_ACCECN_OUT_NOECN. After this patch, the size of tcp_request_sock remains unchanged and no new holes are added. Below are the pahole outcomes before and after this patch: [BEFORE THIS PATCH] struct tcp_request_sock { [...] u32 rcv_nxt; /* 352 4 */ u8 syn_tos; /* 356 1 */ /* size: 360, cachelines: 6, members: 16 */ } [AFTER THIS PATCH] struct tcp_request_sock { [...] u32 rcv_nxt; /* 352 4 */ u8 syn_tos; /* 356 1 */ bool accecn_ok; /* 357 1 */ u8 syn_ect_snt:2; /* 358: 0 1 */ u8 syn_ect_rcv:2; /* 358: 2 1 */ u8 accecn_fail_mode:4; /* 358: 4 1 */ /* size: 360, cachelines: 6, members: 20 */ } After this patch, the size of tcp_sock remains unchanged and no new holes are added. Also, 4 bits of the existing 2-byte hole are exploited. Below are the pahole outcomes before and after this patch: [BEFORE THIS PATCH] struct tcp_sock { [...] u8 dup_ack_counter:2; /* 2761: 0 1 */ u8 tlp_retrans:1; /* 2761: 2 1 */ u8 unused:5; /* 2761: 3 1 */ u8 thin_lto:1; /* 2762: 0 1 */ u8 fastopen_connect:1; /* 2762: 1 1 */ u8 fastopen_no_cookie:1; /* 2762: 2 1 */ u8 fastopen_client_fail:2; /* 2762: 3 1 */ u8 frto:1; /* 2762: 5 1 */ /* XXX 2 bits hole, try to pack */ [...] u8 keepalive_probes; /* 2765 1 */ /* XXX 2 bytes hole, try to pack */ [...] /* size: 3200, cachelines: 50, members: 164 */ } [AFTER THIS PATCH] struct tcp_sock { [...] u8 dup_ack_counter:2; /* 2761: 0 1 */ u8 tlp_retrans:1; /* 2761: 2 1 */ u8 syn_ect_snt:2; /* 2761: 3 1 */ u8 syn_ect_rcv:2; /* 2761: 5 1 */ u8 thin_lto:1; /* 2761: 7 1 */ u8 fastopen_connect:1; /* 2762: 0 1 */ u8 fastopen_no_cookie:1; /* 2762: 1 1 */ u8 fastopen_client_fail:2; /* 2762: 2 1 */ u8 frto:1; /* 2762: 4 1 */ /* XXX 3 bits hole, try to pack */ [...] u8 keepalive_probes; /* 2765 1 */ u8 accecn_fail_mode:4; /* 2766: 0 1 */ /* XXX 4 bits hole, try to pack */ /* XXX 1 byte hole, try to pack */ [...] /* size: 3200, cachelines: 50, members: 166 */ } Signed-off-by: Ilpo Järvinen <ij@kernel.org> Co-developed-by: Olivier Tilmans <olivier.tilmans@nokia.com> Signed-off-by: Olivier Tilmans <olivier.tilmans@nokia.com> Co-developed-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-3-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-18tcp: AccECN coreIlpo Järvinen3-10/+104
This change implements Accurate ECN without negotiation and AccECN Option (that will be added by later changes). Based on AccECN specifications: https://tools.ietf.org/id/draft-ietf-tcpm-accurate-ecn-28.txt Accurate ECN allows feeding back the number of CE (congestion experienced) marks accurately to the sender in contrast to RFC3168 ECN that can only signal one marks-seen-yes/no per RTT. Congestion control algorithms can take advantage of the accurate ECN information to fine-tune their congestion response to avoid drastic rate reduction when only mild congestion is encountered. With Accurate ECN, tp->received_ce (r.cep in AccECN spec) keeps track of how many segments have arrived with a CE mark. Accurate ECN uses ACE field (ECE, CWR, AE) to communicate the value back to the sender which updates tp->delivered_ce (s.cep) based on the feedback. This signalling channel is lossy when ACE field overflow occurs. Conservative strategy is selected here to deal with the ACE overflow, however, some strategies using the AccECN option later in the overall patchset mitigate against false overflows detected. The ACE field values on the wire are offset by TCP_ACCECN_CEP_INIT_OFFSET. Delivered_ce/received_ce count the real CE marks rather than forcing all downstream users to adapt to the wire offset. This patch uses the first 1-byte hole and the last 4-byte hole of the tcp_sock_write_txrx for 'received_ce_pending' and 'received_ce'. Also, the group size of tcp_sock_write_txrx is increased from 91 + 4 to 95 + 4 due to the new u32 received_ce member. Below are the trimmed pahole outcomes before and after this patch. [BEFORE THIS PATCH] struct tcp_sock { [...] __cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2521 0 */ u8 nonagle:4; /* 2521: 0 1 */ u8 rate_app_limited:1; /* 2521: 4 1 */ /* XXX 3 bits hole, try to pack */ /* XXX 2 bytes hole, try to pack */ [...] u32 delivered_ce; /* 2576 4 */ u32 app_limited; /* 2580 4 */ u32 rcv_wnd; /* 2684 4 */ struct tcp_options_received rx_opt; /* 2688 24 */ __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2612 0 */ /* XXX 4 bytes hole, try to pack */ [...] /* size: 3200, cachelines: 50, members: 161 */ } [AFTER THIS PATCH] struct tcp_sock { [...] __cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2521 0 */ u8 nonagle:4; /* 2521: 0 1 */ u8 rate_app_limited:1; /* 2521: 4 1 */ /* XXX 3 bits hole, try to pack */ /* Force alignment to the next boundary: */ u8 :0; u8 received_ce_pending:4;/* 2522: 0 1 */ u8 unused2:4; /* 2522: 4 1 */ /* XXX 1 byte hole, try to pack */ [...] u32 delivered_ce; /* 2576 4 */ u32 received_ce; /* 2580 4 */ u32 app_limited; /* 2584 4 */ u32 rcv_wnd; /* 2588 4 */ struct tcp_options_received rx_opt; /* 2592 24 */ __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2616 0 */ [...] /* size: 3200, cachelines: 50, members: 164 */ } Signed-off-by: Ilpo Järvinen <ij@kernel.org> Co-developed-by: Olivier Tilmans <olivier.tilmans@nokia.com> Signed-off-by: Olivier Tilmans <olivier.tilmans@nokia.com> Co-developed-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-2-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-17tcp: Clear tcp_sk(sk)->fastopen_rsk in tcp_disconnect().Kuniyuki Iwashima1-0/+5
syzbot reported the splat below where a socket had tcp_sk(sk)->fastopen_rsk in the TCP_ESTABLISHED state. [0] syzbot reused the server-side TCP Fast Open socket as a new client before the TFO socket completes 3WHS: 1. accept() 2. connect(AF_UNSPEC) 3. connect() to another destination As of accept(), sk->sk_state is TCP_SYN_RECV, and tcp_disconnect() changes it to TCP_CLOSE and makes connect() possible, which restarts timers. Since tcp_disconnect() forgot to clear tcp_sk(sk)->fastopen_rsk, the retransmit timer triggered the warning and the intended packet was not retransmitted. Let's call reqsk_fastopen_remove() in tcp_disconnect(). [0]: WARNING: CPU: 2 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7)) Modules linked in: CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.17.0-rc5-g201825fb4278 #62 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:tcp_retransmit_timer (net/ipv4/tcp_timer.c:542 (discriminator 7)) Code: 41 55 41 54 55 53 48 8b af b8 08 00 00 48 89 fb 48 85 ed 0f 84 55 01 00 00 0f b6 47 12 3c 03 74 0c 0f b6 47 12 3c 04 74 04 90 <0f> 0b 90 48 8b 85 c0 00 00 00 48 89 ef 48 8b 40 30 e8 6a 4f 06 3e RSP: 0018:ffffc900002f8d40 EFLAGS: 00010293 RAX: 0000000000000002 RBX: ffff888106911400 RCX: 0000000000000017 RDX: 0000000002517619 RSI: ffffffff83764080 RDI: ffff888106911400 RBP: ffff888106d5c000 R08: 0000000000000001 R09: ffffc900002f8de8 R10: 00000000000000c2 R11: ffffc900002f8ff8 R12: ffff888106911540 R13: ffff888106911480 R14: ffff888106911840 R15: ffffc900002f8de0 FS: 0000000000000000(0000) GS:ffff88907b768000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8044d69d90 CR3: 0000000002c30003 CR4: 0000000000370ef0 Call Trace: <IRQ> tcp_write_timer (net/ipv4/tcp_timer.c:738) call_timer_fn (kernel/time/timer.c:1747) __run_timers (kernel/time/timer.c:1799 kernel/time/timer.c:2372) timer_expire_remote (kernel/time/timer.c:2385 kernel/time/timer.c:2376 kernel/time/timer.c:2135) tmigr_handle_remote_up (kernel/time/timer_migration.c:944 kernel/time/timer_migration.c:1035) __walk_groups.isra.0 (kernel/time/timer_migration.c:533 (discriminator 1)) tmigr_handle_remote (kernel/time/timer_migration.c:1096) handle_softirqs (./arch/x86/include/asm/jump_label.h:36 ./include/trace/events/irq.h:142 kernel/softirq.c:580) irq_exit_rcu (kernel/softirq.c:614 kernel/softirq.c:453 kernel/softirq.c:680 kernel/softirq.c:696) sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1050 (discriminator 35) arch/x86/kernel/apic/apic.c:1050 (discriminator 35)) </IRQ> Fixes: 8336886f786f ("tcp: TCP Fast Open Server - support TFO listeners") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250915175800.118793-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-15tcp: ecn functions in separated include fileChia-Yu Chang2-99/+2
The following patches will modify ECN helpers and add AccECN herlpers, and this patch moves the existing ones into a separated include file. No functional changes. Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250911110642.87529-5-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-15tcp: reorganize tcp_sock_write_txrx group for variables laterChia-Yu Chang1-2/+2
Use the first 3-byte hole at the beginning of the tcp_sock_write_txrx group for 'noneagle'/'rate_app_limited' to fill in the existing hole in later patches. Therefore, the group size of tcp_sock_write_txrx is reduced from 92 + 4 to 91 + 4. In addition, the group size of tcp_sock_write_rx is changed to 96 to fit in the pahole outcome. Below are the trimmed pahole outcomes before and after this patch: [BEFORE THIS PATCH] struct tcp_sock { [...] __cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2521 0 */ /* XXX 3 bytes hole, try to pack */ [...] struct tcp_options_received rx_opt; /* 2588 24 */ u8 nonagle:4; /* 2612: 0 1 */ u8 rate_app_limited:1; /* 2612: 4 1 */ /* XXX 3 bits hole, try to pack */ __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2613 0 */ /* XXX 3 bytes hole, try to pack */ __cacheline_group_begin__tcp_sock_write_rx[0] __attribute__((__aligned__(8))); /* 2616 0 */ [...] __cacheline_group_end__tcp_sock_write_rx[0]; /* 2712 0 */ [...] /* size: 3200, cachelines: 50, members: 161 */ } [AFTER THIS PATCH] struct tcp_sock { [...] __cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2521 0 */ u8 nonagle:4; /* 2521: 0 1 */ u8 rate_app_limited:1; /* 2521: 4 1 */ /* XXX 3 bits hole, try to pack */ /* XXX 2 bytes hole, try to pack */ [...] struct tcp_options_received rx_opt; /* 2588 24 */ __cacheline_group_end__tcp_sock_write_txrx[0]; /* 2612 0 */ /* XXX 4 bytes hole, try to pack */ __cacheline_group_begin__tcp_sock_write_rx[0] __attribute__((__aligned__(8))); /* 2616 0 */ [...] __cacheline_group_end__tcp_sock_write_rx[0]; /* 2712 0 */ [...] /* size: 3200, cachelines: 50, members: 161 */ } Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250911110642.87529-4-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-15tcp: reorganize SYN ECN codeIlpo Järvinen1-2/+3
Prepare for AccECN that needs to have access here on IP ECN field value which is only available after INET_ECN_xmit(). No functional changes. Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250911110642.87529-2-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-14net/tcp: Fix a NULL pointer dereference when using TCP-AO with TCP_REPAIRAnderson Nascimento1-1/+3
A NULL pointer dereference can occur in tcp_ao_finish_connect() during a connect() system call on a socket with a TCP-AO key added and TCP_REPAIR enabled. The function is called with skb being NULL and attempts to dereference it on tcp_hdr(skb)->seq without a prior skb validation. Fix this by checking if skb is NULL before dereferencing it. The commentary is taken from bpf_skops_established(), which is also called in the same flow. Unlike the function being patched, bpf_skops_established() validates the skb before dereferencing it. int main(void){ struct sockaddr_in sockaddr; struct tcp_ao_add tcp_ao; int sk; int one = 1; memset(&sockaddr,'\0',sizeof(sockaddr)); memset(&tcp_ao,'\0',sizeof(tcp_ao)); sk = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); sockaddr.sin_family = AF_INET; memcpy(tcp_ao.alg_name,"cmac(aes128)",12); memcpy(tcp_ao.key,"ABCDEFGHABCDEFGH",16); tcp_ao.keylen = 16; memcpy(&tcp_ao.addr,&sockaddr,sizeof(sockaddr)); setsockopt(sk, IPPROTO_TCP, TCP_AO_ADD_KEY, &tcp_ao, sizeof(tcp_ao)); setsockopt(sk, IPPROTO_TCP, TCP_REPAIR, &one, sizeof(one)); sockaddr.sin_family = AF_INET; sockaddr.sin_port = htobe16(123); inet_aton("127.0.0.1", &sockaddr.sin_addr); connect(sk,(struct sockaddr *)&sockaddr,sizeof(sockaddr)); return 0; } $ gcc tcp-ao-nullptr.c -o tcp-ao-nullptr -Wall $ unshare -Urn BUG: kernel NULL pointer dereference, address: 00000000000000b6 PGD 1f648d067 P4D 1f648d067 PUD 1982e8067 PMD 0 Oops: Oops: 0000 [#1] SMP NOPTI Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 RIP: 0010:tcp_ao_finish_connect (net/ipv4/tcp_ao.c:1182) Fixes: 7c2ffaf21bd6 ("net/tcp: Calculate TCP-AO traffic keys") Signed-off-by: Anderson Nascimento <anderson@allelesecurity.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250911230743.2551-3-anderson@allelesecurity.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-12Merge tag 'nf-next-25-09-11' of ↵Jakub Kicinski1-0/+25
https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next Florian Westphal says: ==================== netfilter: updates for net-next 1) Don't respond to ICMP_UNREACH errors with another ICMP_UNREACH error. 2) Support fetching the current bridge ethernet address. This allows a more flexible approach to packet redirection on bridges without need to use hardcoded addresses. From Fernando Fernandez Mancera. 3) Zap a few no-longer needed conditionals from ipvs packet path and convert to READ/WRITE_ONCE to avoid KCSAN warnings. From Zhang Tengfei. 4) Remove a no-longer-used macro argument in ipset, from Zhen Ni. * tag 'nf-next-25-09-11' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_reject: don't reply to icmp error messages ipvs: Use READ_ONCE/WRITE_ONCE for ipvs->enable netfilter: nft_meta_bridge: introduce NFT_META_BRI_IIFHWADDR support netfilter: ipset: Remove unused htable_bits in macro ahash_region selftest:net: fixed spelling mistakes ==================== Link: https://patch.msgid.link/20250911143819.14753-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11udp_tunnel: use netdev_warn() instead of netdev_WARN()Alok Tiwari1-1/+1
netdev_WARN() uses WARN/WARN_ON to print a backtrace along with file and line information. In this case, udp_tunnel_nic_register() returning an error is just a failed operation, not a kernel bug. udp_tunnel_nic_register() can fail due to a memory allocation failure (kzalloc() or udp_tunnel_nic_alloc()). This is a normal runtime error and not a kernel bug. Replace netdev_WARN() with netdev_warn() accordingly. Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250910195031.3784748-1-alok.a.tiwari@oracle.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11tcp: Free TCP-AO/TCP-MD5 info/keys without RCUDmitry Safonov4-33/+12
Now that the destruction of info/keys is delayed until the socket destructor, it's safe to use kfree() without an RCU callback. The socket is in TCP_CLOSE state either because it never left it, or it's already closed and the refcounter is zero. In any way, no one can discover it anymore, it's safe to release memory straight away. Similar thing was possible for twsk already. Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://patch.msgid.link/20250909-b4-tcp-ao-md5-rst-finwait2-v5-2-9ffaaaf8b236@arista.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11tcp: Destroy TCP-AO, TCP-MD5 keys in .sk_destruct()Dmitry Safonov2-25/+35
Currently there are a couple of minor issues with destroying the keys tcp_v4_destroy_sock(): 1. The socket is yet in TCP bind buckets, making it reachable for incoming segments [on another CPU core], potentially available to send late FIN/ACK/RST replies. 2. There is at least one code path, where tcp_done() is called before sending RST [kudos to Bob for investigation]. This is a case of a server, that finished sending its data and just called close(). The socket is in TCP_FIN_WAIT2 and has RCV_SHUTDOWN (set by __tcp_close()) tcp_v4_do_rcv()/tcp_v6_do_rcv() tcp_rcv_state_process() /* LINUX_MIB_TCPABORTONDATA */ tcp_reset() tcp_done_with_error() tcp_done() inet_csk_destroy_sock() /* Destroys AO/MD5 keys */ /* tcp_rcv_state_process() returns SKB_DROP_REASON_TCP_ABORT_ON_DATA */ tcp_v4_send_reset() /* Sends an unsigned RST segment */ tcpdump: > 22:53:15.399377 00:00:b2:1f:00:00 > 00:00:01:01:00:00, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 64, id 33929, offset 0, flags [DF], proto TCP (6), length 60) > 1.0.0.1.34567 > 1.0.0.2.49848: Flags [F.], seq 2185658590, ack 3969644355, win 502, options [nop,nop,md5 valid], length 0 > 22:53:15.399396 00:00:01:01:00:00 > 00:00:b2:1f:00:00, ethertype IPv4 (0x0800), length 86: (tos 0x0, ttl 64, id 51951, offset 0, flags [DF], proto TCP (6), length 72) > 1.0.0.2.49848 > 1.0.0.1.34567: Flags [.], seq 3969644375, ack 2185658591, win 128, options [nop,nop,md5 valid,nop,nop,sack 1 {2185658590:2185658591}], length 0 > 22:53:16.429588 00:00:b2:1f:00:00 > 00:00:01:01:00:00, ethertype IPv4 (0x0800), length 60: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 40) > 1.0.0.1.34567 > 1.0.0.2.49848: Flags [R], seq 2185658590, win 0, length 0 > 22:53:16.664725 00:00:b2:1f:00:00 > 00:00:01:01:00:00, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 60) > 1.0.0.1.34567 > 1.0.0.2.49848: Flags [R], seq 2185658591, win 0, options [nop,nop,md5 valid], length 0 > 22:53:17.289832 00:00:b2:1f:00:00 > 00:00:01:01:00:00, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 60) > 1.0.0.1.34567 > 1.0.0.2.49848: Flags [R], seq 2185658591, win 0, options [nop,nop,md5 valid], length 0 Note the signed RSTs later in the dump - those are sent by the server when the fin-wait socket gets removed from hash buckets, by the listener socket. Instead of destroying AO/MD5 info and their keys in inet_csk_destroy_sock(), slightly delay it until the actual socket .sk_destruct(). As shutdown'ed socket can yet send non-data replies, they should be signed in order for the peer to process them. Now it also matches how AO/MD5 gets destructed for TIME-WAIT sockets (in tcp_twsk_destructor()). This seems optimal for TCP-MD5, while for TCP-AO it seems to have an open problem: once RST get sent and socket gets actually destructed, there is no information on the initial sequence numbers. So, in case this last RST gets lost in the network, the server's listener socket won't be able to properly sign another RST. Nothing in RFC 1122 prescribes keeping any local state after non-graceful reset. Luckily, BGP are known to use keep alive(s). While the issue is quite minor/cosmetic, these days monitoring network counters is a common practice and getting invalid signed segments from a trusted BGP peer can get customers worried. Investigated-by: Bob Gilligan <gilligan@arista.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://patch.msgid.link/20250909-b4-tcp-ao-md5-rst-finwait2-v5-1-9ffaaaf8b236@arista.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11net: devmem: expose tcp_recvmsg_locked errorsStanislav Fomichev1-2/+2
tcp_recvmsg_dmabuf can export the following errors: - EFAULT when linear copy fails - ETOOSMALL when cmsg put fails - ENODEV if one of the frags is readable - ENOMEM on xarray failures But they are all ignored and replaced by EFAULT in the caller (tcp_recvmsg_locked). Expose real error to the userspace to add more transparency on what specifically fails. In non-devmem case (skb_copy_datagram_msg) doing `if (!copied) copied=-EFAULT` is ok because skb_copy_datagram_msg can return only EFAULT. Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250910162429.4127997-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-1/+10
Cross-merge networking fixes after downstream PR (net-6.17-rc6). Conflicts: net/netfilter/nft_set_pipapo.c net/netfilter/nft_set_pipapo_avx2.c c4eaca2e1052 ("netfilter: nft_set_pipapo: don't check genbit from packetpath lookups") 84c1da7b38d9 ("netfilter: nft_set_pipapo: use avx2 algorithm for insertions too") Only trivial adjacent changes (in a doc and a Makefile). Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11Merge tag 'net-6.17-rc6' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from CAN, netfilter and wireless. We have an IPv6 routing regression with the relevant fix still a WiP. This includes a last-minute revert to avoid more problems. Current release - new code bugs: - wifi: nl80211: completely disable per-link stats for now Previous releases - regressions: - dev_ioctl: take ops lock in hwtstamp lower paths - netfilter: - fix spurious set lookup failures - fix lockdep splat due to missing annotation - genetlink: fix genl_bind() invoking bind() after -EPERM - phy: transfer phy_config_inband() locking responsibility to phylink - can: xilinx_can: fix use-after-free of transmitted SKB - hsr: fix lock warnings - eth: - igb: fix NULL pointer dereference in ethtool loopback test - i40e: fix Jumbo Frame support after iPXE boot - macsec: sync features on RTM_NEWLINK Previous releases - always broken: - tunnels: reset the GSO metadata before reusing the skb - mptcp: make sync_socket_options propagate SOCK_KEEPOPEN - can: j1939: implement NETDEV_UNREGISTER notification hanidler - wifi: ath12k: fix WMI TLV header misalignment" * tag 'net-6.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (47 commits) Revert "net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups" hsr: hold rcu and dev lock for hsr_get_port_ndev hsr: use hsr_for_each_port_rtnl in hsr_port_get_hsr hsr: use rtnl lock when iterating over ports wifi: nl80211: completely disable per-link stats for now net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups net: ethtool: fix wrong type used in struct kernel_ethtool_ts_info MAINTAINERS: add Phil as netfilter reviewer netfilter: nf_tables: restart set lookup on base_seq change netfilter: nf_tables: make nft_set_do_lookup available unconditionally netfilter: nf_tables: place base_seq in struct net netfilter: nft_set_rbtree: continue traversal if element is inactive netfilter: nft_set_pipapo: don't check genbit from packetpath lookups netfilter: nft_set_bitmap: fix lockdep splat due to missing annotation can: rcar_can: rcar_can_resume(): fix s2ram with PSCI can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB can: j1939: j1939_local_ecu_get(): undo increment when j1939_local_ecu_get() fails can: j1939: j1939_sk_bind(): call j1939_priv_put() immediately when j1939_local_ecu_get() failed can: j1939: implement NETDEV_UNREGISTER notification handler selftests: can: enable CONFIG_CAN_VCAN as a module ...
2025-09-11Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds1-1/+4
Pull bpf fixes from Alexei Starovoitov: "A number of fixes accumulated due to summer vacations - Fix out-of-bounds dynptr write in bpf_crypto_crypt() kfunc which was misidentified as a security issue (Daniel Borkmann) - Update the list of BPF selftests maintainers (Eduard Zingerman) - Fix selftests warnings with icecc compiler (Ilya Leoshkevich) - Disable XDP/cpumap direct return optimization (Jesper Dangaard Brouer) - Fix unexpected get_helper_proto() result in unusual configuration BPF_SYSCALL=y and BPF_EVENTS=n (Jiri Olsa) - Allow fallback to interpreter when JIT support is limited (KaFai Wan) - Fix rqspinlock and choose trylock fallback for NMI waiters. Pick the simplest fix. More involved fix is targeted bpf-next (Kumar Kartikeya Dwivedi) - Fix cleanup when tcp_bpf_send_verdict() fails to allocate psock->cork (Kuniyuki Iwashima) - Disallow bpf_timer in PREEMPT_RT for now. Proper solution is being discussed for bpf-next. (Leon Hwang) - Fix XSK cq descriptor production (Maciej Fijalkowski) - Tell memcg to use allow_spinning=false path in bpf_timer_init() to avoid lockup in cgroup_file_notify() (Peilin Ye) - Fix bpf_strnstr() to handle suffix match cases (Rong Tao)" * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: Skip timer cases when bpf_timer is not supported bpf: Reject bpf_timer for PREEMPT_RT tcp_bpf: Call sk_msg_free() when tcp_bpf_send_verdict() fails to allocate psock->cork. bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init() bpf: Allow fall back to interpreter for programs with stack size <= 512 rqspinlock: Choose trylock fallback for NMI waiters xsk: Fix immature cq descriptor production bpf: Update the list of BPF selftests maintainers selftests/bpf: Add tests for bpf_strnstr selftests/bpf: Fix "expression result unused" warnings with icecc bpf: Fix bpf_strnstr() to handle suffix match cases better selftests/bpf: Extend crypto_sanity selftest with invalid dst buffer bpf: Fix out-of-bounds dynptr write in bpf_crypto_crypt bpf: Check the helper function is valid in get_helper_proto bpf, cpumap: Disable page_pool direct xdp_return need larger scope
2025-09-11netfilter: nf_reject: don't reply to icmp error messagesFlorian Westphal1-0/+25
tcp reject code won't reply to a tcp reset. But the icmp reject 'netdev' family versions will reply to icmp dst-unreach errors, unlike icmp_send() and icmp6_send() which are used by the inet family implementation (and internally by the REJECT target). Check for the icmp(6) type and do not respond if its an unreachable error. Without this, something like 'ip protocol icmp reject', when used in a netdev chain attached to 'lo', cause a packet loop. Same for two hosts that both use such a rule: each error packet will be replied to. Such situation persist until the (bogus) rule is amended to ratelimit or checks the icmp type before the reject statement. As the inet versions don't do this make the netdev ones follow along. Signed-off-by: Florian Westphal <fw@strlen.de>
2025-09-11ipv4: icmp: Fix source IP derivation in presence of VRFsIdo Schimmel1-1/+2
When the "icmp_errors_use_inbound_ifaddr" sysctl is enabled, the source IP of ICMP error messages should be the "primary address of the interface that received the packet that caused the icmp error". The IPv4 ICMP code determines this interface using inet_iif() which in the input path translates to skb->skb_iif. If the interface that received the packet is a VRF port, skb->skb_iif will contain the ifindex of the VRF device and not that of the receiving interface. This is because in the input path the VRF driver overrides skb->skb_iif with the ifindex of the VRF device itself (see vrf_ip_rcv()). As such, the source IP that will be chosen for the ICMP error message is either an address assigned to the VRF device itself (if present) or an address assigned to some VRF port, not necessarily the input or output interface. This behavior is especially problematic when the error messages are "Time Exceeded" messages as it means that utilities like traceroute will show an incorrect packet path. Solve this by determining the input interface based on the iif field in the control block, if present. This field is set in the input path to skb->skb_iif and is not later overridden by the VRF driver, unlike skb->skb_iif. This behavior is consistent with the IPv6 counterpart that already uses the iif from the control block. Reported-by: Andy Roulin <aroulin@nvidia.com> Reported-by: Rajkumar Srinivasan <rajsrinivasa@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250908073238.119240-4-idosch@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-11ipv4: icmp: Pass IPv4 control block structure as an argument to __icmp_send()Ido Schimmel3-16/+18
__icmp_send() is used to generate ICMP error messages in response to various situations such as MTU errors (i.e., "Fragmentation Required") and too many hops (i.e., "Time Exceeded"). The skb that generated the error does not necessarily come from the IPv4 layer and does not always have a valid IPv4 control block in skb->cb. Therefore, commit 9ef6b42ad6fd ("net: Add __icmp_send helper.") changed the function to take the IP options structure as argument instead of deriving it from the skb's control block. Some callers of this function such as icmp_send() pass the IP options structure from the skb's control block as in these call paths the control block is known to be valid, but other callers simply pass a zeroed structure. A subsequent patch will need __icmp_send() to access more information from the IPv4 control block (specifically, the ifindex of the input interface). As a preparation for this change, change the function to take the IPv4 control block structure as an argument instead of the IP options structure. This makes the function similar to its IPv6 counterpart that already takes the IPv6 control block structure as an argument. No functional changes intended. Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250908073238.119240-3-idosch@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-11ipv4: cipso: Simplify IP options handling in cipso_v4_error()Ido Schimmel1-7/+6
When __ip_options_compile() is called with an skb, the IP options are parsed from the skb data into the provided IP option argument. This is in contrast to the case where the skb argument is NULL and the options are parsed from opt->__data. Given that cipso_v4_error() always passes an skb to __ip_options_compile(), there is no need to allocate an extra 40 bytes (maximum IP options size). Therefore, simplify the function by removing these extra bytes and make the function similar to ipv4_send_dest_unreach() which also calls both __ip_options_compile() and __icmp_send(). This is a preparation for changing the arguments being passed to __icmp_send(). No functional changes intended. Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250908073238.119240-2-idosch@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-10tcp_bpf: Call sk_msg_free() when tcp_bpf_send_verdict() fails to allocate ↵Kuniyuki Iwashima1-1/+4
psock->cork. syzbot reported the splat below. [0] The repro does the following: 1. Load a sk_msg prog that calls bpf_msg_cork_bytes(msg, cork_bytes) 2. Attach the prog to a SOCKMAP 3. Add a socket to the SOCKMAP 4. Activate fault injection 5. Send data less than cork_bytes At 5., the data is carried over to the next sendmsg() as it is smaller than the cork_bytes specified by bpf_msg_cork_bytes(). Then, tcp_bpf_send_verdict() tries to allocate psock->cork to hold the data, but this fails silently due to fault injection + __GFP_NOWARN. If the allocation fails, we need to revert the sk->sk_forward_alloc change done by sk_msg_alloc(). Let's call sk_msg_free() when tcp_bpf_send_verdict fails to allocate psock->cork. The "*copied" also needs to be updated such that a proper error can be returned to the caller, sendmsg. It fails to allocate psock->cork. Nothing has been corked so far, so this patch simply sets "*copied" to 0. [0]: WARNING: net/ipv4/af_inet.c:156 at inet_sock_destruct+0x623/0x730 net/ipv4/af_inet.c:156, CPU#1: syz-executor/5983 Modules linked in: CPU: 1 UID: 0 PID: 5983 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:inet_sock_destruct+0x623/0x730 net/ipv4/af_inet.c:156 Code: 0f 0b 90 e9 62 fe ff ff e8 7a db b5 f7 90 0f 0b 90 e9 95 fe ff ff e8 6c db b5 f7 90 0f 0b 90 e9 bb fe ff ff e8 5e db b5 f7 90 <0f> 0b 90 e9 e1 fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 9f fc RSP: 0018:ffffc90000a08b48 EFLAGS: 00010246 RAX: ffffffff8a09d0b2 RBX: dffffc0000000000 RCX: ffff888024a23c80 RDX: 0000000000000100 RSI: 0000000000000fff RDI: 0000000000000000 RBP: 0000000000000fff R08: ffff88807e07c627 R09: 1ffff1100fc0f8c4 R10: dffffc0000000000 R11: ffffed100fc0f8c5 R12: ffff88807e07c380 R13: dffffc0000000000 R14: ffff88807e07c60c R15: 1ffff1100fc0f872 FS: 00005555604c4500(0000) GS:ffff888125af1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555604df5c8 CR3: 0000000032b06000 CR4: 00000000003526f0 Call Trace: <IRQ> __sk_destruct+0x86/0x660 net/core/sock.c:2339 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xca8/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 </IRQ> Fixes: 4f738adba30a ("bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data") Reported-by: syzbot+4cabd1d2fa917a456db8@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68c0b6b5.050a0220.3c6139.0013.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20250909232623.4151337-1-kuniyu@google.com
2025-09-09ipv4: udp: fix typos in commentsAlok Tiwari1-3/+3
Correct typos in ipv4/udp.c comments for clarity: "Encapulation" -> "Encapsulation" "measureable" -> "measurable" "tacking care" -> "taking care" No functional changes. Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250907192535.3610686-1-alok.a.tiwari@oracle.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-09tunnels: reset the GSO metadata before reusing the skbAntoine Tenart1-0/+6
If a GSO skb is sent through a Geneve tunnel and if Geneve options are added, the split GSO skb might not fit in the MTU anymore and an ICMP frag needed packet can be generated. In such case the ICMP packet might go through the segmentation logic (and dropped) later if it reaches a path were the GSO status is checked and segmentation is required. This is especially true when an OvS bridge is used with a Geneve tunnel attached to it. The following set of actions could lead to the ICMP packet being wrongfully segmented: 1. An skb is constructed by the TCP layer (e.g. gso_type SKB_GSO_TCPV4, segs >= 2). 2. The skb hits the OvS bridge where Geneve options are added by an OvS action before being sent through the tunnel. 3. When the skb is xmited in the tunnel, the split skb does not fit anymore in the MTU and iptunnel_pmtud_build_icmp is called to generate an ICMP fragmentation needed packet. This is done by reusing the original (GSO!) skb. The GSO metadata is not cleared. 4. The ICMP packet being sent back hits the OvS bridge again and because skb_is_gso returns true, it goes through queue_gso_packets... 5. ...where __skb_gso_segment is called. The skb is then dropped. 6. Note that in the above example on re-transmission the skb won't be a GSO one as it would be segmented (len > MSS) and the ICMP packet should go through. Fix this by resetting the GSO information before reusing an skb in iptunnel_pmtud_build_icmp and iptunnel_pmtud_build_icmpv6. Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets") Reported-by: Adrian Moreno <amorenoz@redhat.com> Signed-off-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Link: https://patch.msgid.link/20250904125351.159740-1-atenart@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-09-08ipv4: snmp: do not use SNMP_MIB_SENTINEL anymoreEric Dumazet1-32/+33
Use ARRAY_SIZE(), so that we know the limit at compile time. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250905165813.1470708-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-04tcp: use tcp_eat_recv_skb in __tcp_close()Eric Dumazet1-2/+2
Small change to use tcp_eat_recv_skb() instead of __kfree_skb(). This can help if an application under attack has to close many sockets with unread data. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20250903084720.1168904-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-04tcp: fix __tcp_close() to only send RST when requiredEric Dumazet1-4/+5
If the receive queue contains payload that was already received, __tcp_close() can send an unexpected RST. Refine the code to take tp->copied_seq into account, as we already do in tcp recvmsg(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20250903084720.1168904-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-6/+7
Cross-merge networking fixes after downstream PR (net-6.17-rc5). No conflicts. Adjacent changes: include/net/sock.h c51613fa276f ("net: add sk->sk_drop_counters") 5d6b58c932ec ("net: lockless sock_i_ino()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-03ipv4: Fix NULL vs error pointer check in inet_blackhole_dev_init()Dan Carpenter1-4/+3
The inetdev_init() function never returns NULL. Check for error pointers instead. Fixes: 22600596b675 ("ipv4: give an IPv4 dev to blackhole_netdev") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/aLaQWL9NguWmeM1i@stanley.mountain Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-03Merge tag 'nf-next-25-09-02' of ↵Jakub Kicinski1-10/+17
https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next Florian Westphal says: ==================== netfilter: updates for net-next 1) prefer vmalloc_array in ebtables, from Qianfeng Rong. 2) Use csum_replace4 instead of open-coding it, from Christophe Leroy. 3+4) Get rid of GFP_ATOMIC in transaction object allocations, those cause silly failures with large sets under memory pressure, from myself. 5) Remove test for AVX cpu feature in nftables pipapo set type, testing for AVX2 feature is sufficient. 6) Unexport a few function in nf_reject infra: no external callers. 7) Extend payload offset to u16, this was restricted to values <=255 so far, from Fernando Fernandez Mancera. * tag 'nf-next-25-09-02' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nft_payload: extend offset to 65535 bytes netfilter: nf_reject: remove unneeded exports netfilter: nft_set_pipapo: remove redundant test for avx feature bit netfilter: nf_tables: all transaction allocations can now sleep netfilter: nf_tables: allow iter callbacks to sleep netfilter: nft_payload: Use csum_replace4() instead of opencoding netfilter: ebtables: Use vmalloc_array() to improve code ==================== Link: https://patch.msgid.link/20250902133549.15945-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-03netlink: specs: fou: change local-v6/peer-v6 checkAsbjørn Sloth Tønnesen1-2/+2
While updating the binary min-len implementation, I noticed that the only user, should AFAICT be using exact-len instead. In net/ipv4/fou_core.c FOU_ATTR_LOCAL_V6 and FOU_ATTR_PEER_V6 are only used for singular IPv6 addresses, and there are AFAICT no known implementations trying to send more, it therefore appears safe to change it to an exact-len policy. This patch therefore changes the local-v6/peer-v6 attributes to use an exact-len check, instead of a min-len check. Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> Reviewed-by: Donald Hunter <donald.hunter@gmail.com> Link: https://patch.msgid.link/20250902154640.759815-2-ast@fiberby.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-02netfilter: nf_reject: remove unneeded exportsFlorian Westphal1-10/+17
These functions have no external callers and can be static. Signed-off-by: Florian Westphal <fw@strlen.de>
2025-09-01inet: ping: use EXPORT_IPV6_MOD[_GPL]()Eric Dumazet1-16/+16
There is no neeed to export ping symbols when CONFIG_IPV6=y Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250829153054.474201-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-01inet: ping: make ping_port_rover per netnsEric Dumazet1-5/+5
Provide isolation between netns for ping idents. Randomize initial ping_port_rover value at netns creation. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250829153054.474201-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-01inet: ping: remove ping_hash()Eric Dumazet1-10/+0
There is no point in keeping ping_hash(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Link: https://patch.msgid.link/20250829153054.474201-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-01inet: ping: check sock_net() in ping_get_port() and ping_lookup()Eric Dumazet1-4/+10
We need to check socket netns before considering them in ping_get_port(). Otherwise, one malicious netns could 'consume' all ports. Add corresponding check in ping_lookup(). Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Link: https://patch.msgid.link/20250829153054.474201-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-01icmp: fix icmp_ndo_send address translation for reply directionFabian Bläse1-2/+4
The icmp_ndo_send function was originally introduced to ensure proper rate limiting when icmp_send is called by a network device driver, where the packet's source address may have already been transformed by SNAT. However, the original implementation only considers the IP_CT_DIR_ORIGINAL direction for SNAT and always replaced the packet's source address with that of the original-direction tuple. This causes two problems: 1. For SNAT: Reply-direction packets were incorrectly translated using the source address of the CT original direction, even though no translation is required. 2. For DNAT: Reply-direction packets were not handled at all. In DNAT, the original direction's destination is translated. Therefore, in the reply direction the source address must be set to the reply-direction source, so rate limiting works as intended. Fix this by using the connection direction to select the correct tuple for source address translation, and adjust the pre-checks to handle reply-direction packets in case of DNAT. Additionally, wrap the `ct->status` access in READ_ONCE(). This avoids possible KCSAN reports about concurrent updates to `ct->status`. Fixes: 0b41713b6066 ("icmp: introduce helper for nat'd source address in network device context") Signed-off-by: Fabian Bläse <fabian@blaese.de> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-01tcp: Remove sk->sk_prot->orphan_count.Kuniyuki Iwashima4-5/+11
TCP tracks the number of orphaned (SOCK_DEAD but not yet destructed) sockets in tcp_orphan_count. In some code that was shared with DCCP, tcp_orphan_count is referenced via sk->sk_prot->orphan_count. Let's reference tcp_orphan_count directly. inet_csk_prepare_for_destroy_sock() is moved to inet_connection_sock.c due to header dependency. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250829215641.711664-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29ipv4: start using dst_dev_rcu()Eric Dumazet4-10/+12
Change icmpv4_xrlim_allow(), ip_defrag() to prevent possible UAF. Change ipmr_prepare_xmit(), ipmr_queue_fwd_xmit(), ip_mr_output(), ipv4_neigh_lookup() to use lockdep enabled dst_dev_rcu(). Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250828195823.3958522-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29tcp: use dst_dev_rcu() in tcp_fastopen_active_disable_ofo_check()Eric Dumazet1-3/+4
Use RCU to avoid a pair of atomic operations and a potential UAF on dst_dev()->flags. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250828195823.3958522-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29tcp_metrics: use dst_dev_net_rcu()Eric Dumazet1-3/+3
Replace three dst_dev() with a lockdep enabled helper. Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250828195823.3958522-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29net: dst: introduce dst->dev_rcuEric Dumazet1-2/+2
Followup of commit 88fe14253e18 ("net: dst: add four helpers to annotate data-races around dst->dev"). We want to gradually add explicit RCU protection to dst->dev, including lockdep support. Add an union to alias dst->dev_rcu and dst->dev. Add dst_dev_net_rcu() helper. Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250828195823.3958522-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29inet_diag: avoid cache line misses in inet_diag_bc_sk()Eric Dumazet1-21/+31
inet_diag_bc_sk() pulls five cache lines per socket, while most filters only need the two first ones. Add three booleans to struct inet_diag_dump_data, that are selectively set if a filter needs specific socket fields. - mark_needed /* INET_DIAG_BC_MARK_COND present. */ - cgroup_needed /* INET_DIAG_BC_CGROUP_COND present. */ - userlocks_needed /* INET_DIAG_BC_AUTO present. */ This removes millions of cache lines misses per ss invocation when simple filters are specified on busy servers. offsetof(struct sock, sk_userlocks) = 0xf3 offsetof(struct sock, sk_mark) = 0x20c offsetof(struct sock, sk_cgrp_data) = 0x298 Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250828102738.2065992-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29inet_diag: change inet_diag_bc_sk() first argumentEric Dumazet4-20/+11
We want to have access to the inet_diag_dump_data structure in the following patch. This patch removes duplication in callers. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250828102738.2065992-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29inet_diag: annotate data-races in inet_diag_bc_sk()Eric Dumazet1-7/+7
inet_diag_bc_sk() runs with an unlocked socket, annotate potential races with READ_ONCE(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250828102738.2065992-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29tcp: annotate data-races in tcp_req_diag_fill()Eric Dumazet2-3/+3
req->num_retrans and rsk_timer.expires are read locklessly, and can be changed from tcp_rtx_synack(). Add READ_ONCE()/WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250828102738.2065992-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29inet_diag: annotate data-races in inet_diag_msg_common_fill()Eric Dumazet1-9/+9
inet_diag_msg_common_fill() can run without socket lock. Add READ_ONCE() or data_race() annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250828102738.2065992-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-3/+7
Cross-merge networking fixes after downstream PR (net-6.17-rc4). No conflicts. Adjacent changes: drivers/net/ethernet/intel/idpf/idpf_txrx.c 02614eee26fb ("idpf: do not linearize big TSO packets") 6c4e68480238 ("idpf: remove obsolete stashing code") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-28inet: raw: add drop_counters to raw socketsEric Dumazet1-0/+1
When a packet flood hits one or more RAW sockets, many cpus have to update sk->sk_drops. This slows down other cpus, because currently sk_drops is in sock_write_rx group. Add a socket_drop_counters structure to raw sockets. Using dedicated cache lines to hold drop counters makes sure that consumers no longer suffer from false sharing if/when producers only change sk->sk_drops. This adds 128 bytes per RAW socket. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250826125031.1578842-6-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-28net: add sk_drops_skbadd() helperEric Dumazet2-3/+3
Existing sk_drops_add() helper is renamed to sk_drops_skbadd(). Add sk_drops_add() and convert sk_drops_inc() to use it. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250826125031.1578842-3-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-28net: add sk_drops_read(), sk_drops_inc() and sk_drops_reset() helpersEric Dumazet3-11/+11
We want to split sk->sk_drops in the future to reduce potential contention on this field. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250826125031.1578842-2-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-28net: ipv4: fix regression in local-broadcast routesOscar Maes1-3/+7
Commit 9e30ecf23b1b ("net: ipv4: fix incorrect MTU in broadcast routes") introduced a regression where local-broadcast packets would have their gateway set in __mkroute_output, which was caused by fi = NULL being removed. Fix this by resetting the fib_info for local-broadcast packets. This preserves the intended changes for directed-broadcast packets. Cc: stable@vger.kernel.org Fixes: 9e30ecf23b1b ("net: ipv4: fix incorrect MTU in broadcast routes") Reported-by: Brett A C Sheffield <bacs@librecast.net> Closes: https://lore.kernel.org/regressions/20250822165231.4353-4-bacs@librecast.net Signed-off-by: Oscar Maes <oscmaes92@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250827062322.4807-1-oscmaes92@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-26ipv4: Convert ->flowi4_tos to dscp_t.Guillaume Nault13-26/+31
Convert the ->flowic_tos field of struct flowi_common from __u8 to dscp_t, rename it ->flowic_dscp and propagate these changes to struct flowi and struct flowi4. We've had several bugs in the past where ECN bits could interfere with IPv4 routing, because these bits were not properly cleared when setting ->flowi4_tos. These bugs should be fixed now and the dscp_t type has been introduced to ensure that variables carrying DSCP values don't accidentally have any ECN bits set. Several variables and structure fields have been converted to dscp_t already, but the main IPv4 routing structure, struct flowi4, is still using a __u8. To avoid any future regression, this patch converts it to dscp_t. There are many users to convert at once. Fortunately, around half of ->flowi4_tos users already have a dscp_t value at hand, which they currently convert to __u8 using inet_dscp_to_dsfield(). For all of these users, we just need to drop that conversion. But, although we try to do the __u8 <-> dscp_t conversions at the boundaries of the network or of user space, some places still store TOS/DSCP variables as __u8 in core networking code. Those can hardly be converted either because the data structure is part of UAPI or because the same variable or field is also used for handling ECN in other parts of the code. In all of these cases where we don't have a dscp_t variable at hand, we need to use inet_dsfield_to_dscp() when interacting with ->flowi4_dscp. Changes since v1: * Fix space alignment in __bpf_redirect_neigh_v4() (Ido). Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/29acecb45e911d17446b9a3dbdb1ab7b821ea371.1756128932.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: Move TCP-specific diag functions to tcp_diag.c.Kuniyuki Iwashima2-484/+455
tcp_diag_dump() / tcp_diag_dump_one() is just a wrapper of inet_diag_dump_icsk() / inet_diag_dump_one_icsk(), respectively. Let's inline them in tcp_diag.c and move static callees as well. Note that inet_sk_attr_size() is merged into tcp_diag_get_aux_size(), and we remove inet_diag_handler.idiag_get_aux_size() accordingly. While at it, BUG_ON() is replaced with DEBUG_NET_WARN_ON_ONCE(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250822190803.540788-7-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: Don't pass hashinfo to inet_diag helpers.Kuniyuki Iwashima2-19/+8
These inet_diag functions required struct inet_hashinfo because they are shared by TCP and DCCP: * inet_diag_dump_icsk() * inet_diag_dump_one_icsk() * inet_diag_find_one_icsk() DCCP has gone, and we don't need to pass hashinfo down to them. Let's fetch net->ipv4.tcp_death_row.hashinfo directly in the first 2 functions. Note that inet_diag_find_one_icsk() don't need hashinfo since the previous patch. We will move TCP-specific functions to tcp_diag.c in the next patch. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250822190803.540788-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: Don't pass hashinfo to socket lookup helpers.Kuniyuki Iwashima7-36/+29
These socket lookup functions required struct inet_hashinfo because they are shared by TCP and DCCP. * __inet_lookup_established() * __inet_lookup_listener() * __inet6_lookup_established() * inet6_lookup_listener() DCCP has gone, and we don't need to pass hashinfo down to them. Let's fetch net->ipv4.tcp_death_row.hashinfo directly in the above 4 functions. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250822190803.540788-5-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: Remove hashinfo test for inet6?_lookup_run_sk_lookup().Kuniyuki Iwashima1-2/+1
Commit 6c886db2e78c ("net: remove duplicate sk_lookup helpers") started to check if hashinfo == net->ipv4.tcp_death_row.hashinfo in __inet_lookup_listener() and inet6_lookup_listener() and stopped invoking BPF sk_lookup prog for DCCP. DCCP has gone and the condition is always true. Let's remove the hashinfo test. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250822190803.540788-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: Remove timewait_sock_ops.twsk_destructor().Kuniyuki Iwashima3-4/+3
Since DCCP has been removed, sk->sk_prot->twsk_prot->twsk_destructor is always tcp_twsk_destructor(). Let's call tcp_twsk_destructor() directly in inet_twsk_free() and remove ->twsk_destructor(). While at it, tcp_twsk_destructor() is un-exported. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250822190803.540788-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: Remove sk_protocol test for tcp_twsk_unique().Kuniyuki Iwashima1-2/+1
Commit 383eed2de529 ("tcp: get rid of twsk_unique()") added sk->sk_protocol test in __inet_check_established() and __inet6_check_established() to remove twsk_unique() and call tcp_twsk_unique() directly. DCCP has gone, and the condition is always true. Let's remove the sk_protocol test. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250822190803.540788-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: annotate data-races around icsk->icsk_probes_outEric Dumazet6-9/+9
icsk->icsk_probes_out is read locklessly from inet_sk_diag_fill(), get_tcp4_sock() and get_tcp6_sock(). Add corresponding READ_ONCE()/WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250822091727.835869-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25tcp: annotate data-races around icsk->icsk_retransmitsEric Dumazet6-8/+9
icsk->icsk_retransmits is read locklessly from inet_sk_diag_fill(), tcp_get_timestamping_opt_stats, get_tcp4_sock() and get_tcp6_sock(). Add corresponding READ_ONCE()/WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250822091727.835869-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25net: ipv4: allow directed broadcast routes to use dst hintOscar Maes2-5/+8
Currently, ip_extract_route_hint uses RTN_BROADCAST to decide whether to use the route dst hint mechanism. This check is too strict, as it prevents directed broadcast routes from using the hint, resulting in poor performance during bursts of directed broadcast traffic. Fix this in ip_extract_route_hint and modify ip_route_use_hint to preserve the intended behaviour. Signed-off-by: Oscar Maes <oscmaes92@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250819174642.5148-2-oscmaes92@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-22tcp: lockless TCP_MAXSEG optionEric Dumazet1-4/+2
setsockopt(TCP_MAXSEG) writes over a field that does not need socket lock protection anymore. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250821141901.18839-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-22tcp: annotate data-races around tp->rx_opt.user_mssEric Dumazet3-9/+13
This field is already read locklessly for listeners, next patch will make setsockopt(TCP_MAXSEG) lockless. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250821141901.18839-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-4/+2
Cross-merge networking fixes after downstream PR (net-6.17-rc3). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-21netfilter: nf_reject: don't leak dst refcount for loopback packetsFlorian Westphal1-4/+2
recent patches to add a WARN() when replacing skb dst entry found an old bug: WARNING: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [inline] WARNING: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [inline] WARNING: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234 [..] Call Trace: nf_send_unreach+0x17b/0x6e0 net/ipv4/netfilter/nf_reject_ipv4.c:325 nft_reject_inet_eval+0x4bc/0x690 net/netfilter/nft_reject_inet.c:27 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] .. This is because blamed commit forgot about loopback packets. Such packets already have a dst_entry attached, even at PRE_ROUTING stage. Instead of checking hook just check if the skb already has a route attached to it. Fixes: f53b9b0bdc59 ("netfilter: introduce support for reject at prerouting stage") Signed-off-by: Florian Westphal <fw@strlen.de> Link: https://patch.msgid.link/20250820123707.10671-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-20net: set net.core.rmem_max and net.core.wmem_max to 4 MBEric Dumazet1-1/+1
SO_RCVBUF and SO_SNDBUF have limited range today, unless distros or system admins change rmem_max and wmem_max. Even iproute2 uses 1 MB SO_RCVBUF which is capped by the kernel. Decouple [rw]mem_max and [rw]mem_default and increase [rw]mem_max to 4 MB. Before: $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max net.core.rmem_default = 212992 net.core.rmem_max = 212992 net.core.wmem_default = 212992 net.core.wmem_max = 212992 After: $ sysctl net.core.rmem_default net.core.rmem_max net.core.wmem_default net.core.wmem_max net.core.rmem_default = 212992 net.core.rmem_max = 4194304 net.core.wmem_default = 212992 net.core.wmem_max = 4194304 Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250819174030.1986278-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net-memcg: Pass struct sock to mem_cgroup_sk_(un)?charge().Kuniyuki Iwashima2-3/+2
We will store a flag in the lowest bit of sk->sk_memcg. Then, we cannot pass the raw pointer to mem_cgroup_charge_skmem() and mem_cgroup_uncharge_skmem(). Let's pass struct sock to the functions. While at it, they are renamed to match other functions starting with mem_cgroup_sk_. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Link: https://patch.msgid.link/20250815201712.1745332-9-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net-memcg: Introduce mem_cgroup_sk_enabled().Kuniyuki Iwashima1-1/+1
The socket memcg feature is enabled by a static key and only works for non-root cgroup. We check both conditions in many places. Let's factorise it as a helper function. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Link: https://patch.msgid.link/20250815201712.1745332-8-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net-memcg: Introduce mem_cgroup_from_sk().Kuniyuki Iwashima1-1/+1
We will store a flag in the lowest bit of sk->sk_memcg. Then, directly dereferencing sk->sk_memcg will be illegal, and we do not want to allow touching the raw sk->sk_memcg in many places. Let's introduce mem_cgroup_from_sk(). Other places accessing the raw sk->sk_memcg will be converted later. Note that we cannot define the helper as an inline function in memcontrol.h as we cannot access any fields of struct sock there due to circular dependency, so it is placed in sock.h. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Link: https://patch.msgid.link/20250815201712.1745332-7-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19tcp: Simplify error path in inet_csk_accept().Kuniyuki Iwashima1-8/+7
When an error occurs in inet_csk_accept(), what we should do is only call release_sock() and set the errno to arg->err. But the path jumps to another label, which introduces unnecessary initialisation and tests for newsk. Let's simplify the error path and remove the redundant NULL checks for newsk. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Link: https://patch.msgid.link/20250815201712.1745332-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net: Switch to skb_dstref_steal/skb_dstref_restore for ip_route_input callersStanislav Fomichev2-6/+6
Going forward skb_dst_set will assert that skb dst_entry is empty during skb_dst_set. skb_dstref_steal is added to reset existing entry without doing refcnt. skb_dstref_restore should be used to restore the previous entry. Convert icmp_route_lookup and ip_options_rcv_srr to these helpers. Add extra call to skb_dstref_reset to icmp_route_lookup to clear the ip_route_input entry. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250818154032.3173645-5-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19netfilter: Switch to skb_dstref_steal to clear dst_entryStanislav Fomichev1-1/+4
Going forward skb_dst_set will assert that skb dst_entry is empty during skb_dst_set. skb_dstref_steal is added to reset existing entry without doing refcnt. Switch to skb_dstref_steal in ip[6]_route_me_harder and add a comment on why it's safe to skip skb_dstref_restore. Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250818154032.3173645-4-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net: When removing nexthops, don't call synchronize_net if it is not necessaryChristoph Paasch1-0/+6
When removing a nexthop, commit 90f33bffa382 ("nexthops: don't modify published nexthop groups") added a call to synchronize_rcu() (later changed to _net()) to make sure everyone sees the new nexthop-group before the rtnl-lock is released. When one wants to delete a large number of groups and nexthops, it is fastest to first flush the groups (ip nexthop flush groups) and then flush the nexthops themselves (ip -6 nexthop flush). As that way the groups don't need to be rebalanced. However, `ip -6 nexthop flush` will still take a long time if there is a very large number of nexthops because of the call to synchronize_net(). Now, if there are no more groups, there is no point in calling synchronize_net(). So, let's skip that entirely by checking if nh->grp_list is empty. This gives us a nice speedup: BEFORE: ======= $ time sudo ip -6 nexthop flush Dump was interrupted and may be inconsistent. Flushed 2097152 nexthops real 1m45.345s user 0m0.001s sys 0m0.005s $ time sudo ip -6 nexthop flush Dump was interrupted and may be inconsistent. Flushed 4194304 nexthops real 3m10.430s user 0m0.002s sys 0m0.004s AFTER: ====== $ time sudo ip -6 nexthop flush Dump was interrupted and may be inconsistent. Flushed 2097152 nexthops real 0m17.545s user 0m0.003s sys 0m0.003s $ time sudo ip -6 nexthop flush Dump was interrupted and may be inconsistent. Flushed 4194304 nexthops real 0m35.823s user 0m0.002s sys 0m0.004s Signed-off-by: Christoph Paasch <cpaasch@openai.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250816-nexthop_dump-v2-2-491da3462118@openai.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19net: Make nexthop-dumps scale linearly with the number of nexthopsChristoph Paasch1-3/+33
When we have a (very) large number of nexthops, they do not fit within a single message. rtm_dump_walk_nexthops() thus will be called repeatedly and ctx->idx is used to avoid dumping the same nexthops again. The approach in which we avoid dumping the same nexthops is by basically walking the entire nexthop rb-tree from the left-most node until we find a node whose id is >= s_idx. That does not scale well. Instead of this inefficient approach, rather go directly through the tree to the nexthop that should be dumped (the one whose nh_id >= s_idx). This allows us to find the relevant node in O(log(n)). We have quite a nice improvement with this: Before: ======= --> ~1M nexthops: $ time ~/libnl/src/nl-nh-list | wc -l 1050624 real 0m21.080s user 0m0.666s sys 0m20.384s --> ~2M nexthops: $ time ~/libnl/src/nl-nh-list | wc -l 2101248 real 1m51.649s user 0m1.540s sys 1m49.908s After: ====== --> ~1M nexthops: $ time ~/libnl/src/nl-nh-list | wc -l 1050624 real 0m1.157s user 0m0.926s sys 0m0.259s --> ~2M nexthops: $ time ~/libnl/src/nl-nh-list | wc -l 2101248 real 0m2.763s user 0m2.042s sys 0m0.776s Signed-off-by: Christoph Paasch <cpaasch@openai.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250816-nexthop_dump-v2-1-491da3462118@openai.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-1/+4
Cross-merge networking fixes after downstream PR (net-6.17-rc2). No conflicts. Adjacent changes: drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c d7a276a5768f ("net: stmmac: rk: convert to suspend()/resume() methods") de1e963ad064 ("net: stmmac: rk: put the PHY clock on remove") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-12tcp: cdg: remove redundant __GFP_NOWARNQianfeng Rong1-1/+1
GFP_NOWAIT already includes __GFP_NOWARN, so let's remove the redundant __GFP_NOWARN. Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250810072944.438574-2-rongqianfeng@vivo.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-12Merge tag 'ipsec-2025-08-11' of ↵Paolo Abeni1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2025-08-11 1) Fix flushing of all states in xfrm_state_fini. From Sabrina Dubroca. 2) Fix some IPsec software offload features. These got lost with some recent HW offload changes. From Sabrina Dubroca. Please pull or let me know if there are problems. * tag 'ipsec-2025-08-11' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: udp: also consider secpath when evaluating ipsec use for checksumming xfrm: bring back device check in validate_xmit_xfrm xfrm: restore GSO for SW crypto xfrm: flush all states in xfrm_state_fini ==================== Link: https://patch.msgid.link/20250811092008.731573-1-steffen.klassert@secunet.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-07netfilter: add back NETFILTER_XTABLES dependenciesArnd Bergmann1-0/+3
Some Kconfig symbols were changed to depend on the 'bool' symbol NETFILTER_XTABLES_LEGACY, which means they can now be set to built-in when the xtables code itself is in a loadable module: x86_64-linux-ld: vmlinux.o: in function `arpt_unregister_table_pre_exit': (.text+0x1831987): undefined reference to `xt_find_table' x86_64-linux-ld: vmlinux.o: in function `get_info.constprop.0': arp_tables.c:(.text+0x1831aab): undefined reference to `xt_request_find_table_lock' x86_64-linux-ld: arp_tables.c:(.text+0x1831bea): undefined reference to `xt_table_unlock' x86_64-linux-ld: vmlinux.o: in function `do_arpt_get_ctl': arp_tables.c:(.text+0x183205d): undefined reference to `xt_find_table_lock' x86_64-linux-ld: arp_tables.c:(.text+0x18320c1): undefined reference to `xt_table_unlock' x86_64-linux-ld: arp_tables.c:(.text+0x183219a): undefined reference to `xt_recseq' Change these to depend on both NETFILTER_XTABLES and NETFILTER_XTABLES_LEGACY. Fixes: 9fce66583f06 ("netfilter: Exclude LEGACY TABLES on PREEMPT_RT.") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Florian Westphal <fw@strlen.de> Tested-by: Breno Leitao <leitao@debian.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-08-07udp: also consider secpath when evaluating ipsec use for checksummingSabrina Dubroca1-1/+1
Commit b40c5f4fde22 ("udp: disable inner UDP checksum offloads in IPsec case") tried to fix checksumming in UFO when the packets are going through IPsec, so that we can't rely on offloads because the UDP header and payload will be encrypted. But when doing a TCP test over VXLAN going through IPsec transport mode with GSO enabled (esp4_offload module loaded), I'm seeing broken UDP checksums on the encap after successful decryption. The skbs get to udp4_ufo_fragment/__skb_udp_tunnel_segment via __dev_queue_xmit -> validate_xmit_skb -> skb_gso_segment and at this point we've already dropped the dst (unless the device sets IFF_XMIT_DST_RELEASE, which is not common), so need_ipsec is false and we proceed with checksum offload. Make need_ipsec also check the secpath, which is not dropped on this callpath. Fixes: b40c5f4fde22 ("udp: disable inner UDP checksum offloads in IPsec case") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2025-08-01net: Add locking to protect skb->dev access in ip_outputSharath Chandra Vurukala1-5/+10
In ip_output() skb->dev is updated from the skb_dst(skb)->dev this can become invalid when the interface is unregistered and freed, Introduced new skb_dst_dev_rcu() function to be used instead of skb_dst_dev() within rcu_locks in ip_output.This will ensure that all the skb's associated with the dev being deregistered will be transnmitted out first, before freeing the dev. Given that ip_output() is called within an rcu_read_lock() critical section or from a bottom-half context, it is safe to introduce an RCU read-side critical section within it. Multiple panic call stacks were observed when UL traffic was run in concurrency with device deregistration from different functions, pasting one sample for reference. [496733.627565][T13385] Call trace: [496733.627570][T13385] bpf_prog_ce7c9180c3b128ea_cgroupskb_egres+0x24c/0x7f0 [496733.627581][T13385] __cgroup_bpf_run_filter_skb+0x128/0x498 [496733.627595][T13385] ip_finish_output+0xa4/0xf4 [496733.627605][T13385] ip_output+0x100/0x1a0 [496733.627613][T13385] ip_send_skb+0x68/0x100 [496733.627618][T13385] udp_send_skb+0x1c4/0x384 [496733.627625][T13385] udp_sendmsg+0x7b0/0x898 [496733.627631][T13385] inet_sendmsg+0x5c/0x7c [496733.627639][T13385] __sys_sendto+0x174/0x1e4 [496733.627647][T13385] __arm64_sys_sendto+0x28/0x3c [496733.627653][T13385] invoke_syscall+0x58/0x11c [496733.627662][T13385] el0_svc_common+0x88/0xf4 [496733.627669][T13385] do_el0_svc+0x2c/0xb0 [496733.627676][T13385] el0_svc+0x2c/0xa4 [496733.627683][T13385] el0t_64_sync_handler+0x68/0xb4 [496733.627689][T13385] el0t_64_sync+0x1a4/0x1a8 Changes in v3: - Replaced WARN_ON() with WARN_ON_ONCE(), as suggested by Willem de Bruijn. - Dropped legacy lines mistakenly pulled in from an outdated branch. Changes in v2: - Addressed review comments from Eric Dumazet - Used READ_ONCE() to prevent potential load/store tearing - Added skb_dst_dev_rcu() and used along with rcu_read_lock() in ip_output Signed-off-by: Sharath Chandra Vurukala <quic_sharathv@quicinc.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250730105118.GA26100@hu-sharathv-hyd.qualcomm.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-25netfilter: Exclude LEGACY TABLES on PREEMPT_RT.Pablo Neira Ayuso1-12/+12
The seqcount xt_recseq is used to synchronize the replacement of xt_table::private in xt_replace_table() against all readers such as ipt_do_table() To ensure that there is only one writer, the writing side disables bottom halves. The sequence counter can be acquired recursively. Only the first invocation modifies the sequence counter (signaling that a writer is in progress) while the following (recursive) writer does not modify the counter. The lack of a proper locking mechanism for the sequence counter can lead to live lock on PREEMPT_RT if the high prior reader preempts the writer. Additionally if the per-CPU lock on PREEMPT_RT is removed from local_bh_disable() then there is no synchronisation for the per-CPU sequence counter. The affected code is "just" the legacy netfilter code which is replaced by "netfilter tables". That code can be disabled without sacrificing functionality because everything is provided by the newer implementation. This will only requires the usage of the "-nft" tools instead of the "-legacy" ones. The long term plan is to remove the legacy code so lets accelerate the progress. Relax dependencies on iptables legacy, replace select with depends on, this should cause no harm to existing kernel configs and users can still toggle IP{6}_NF_IPTABLES_LEGACY in any case. Make EBTABLES_LEGACY, IPTABLES_LEGACY and ARPTABLES depend on NETFILTER_XTABLES_LEGACY. Hide xt_recseq and its users, xt_register_table() and xt_percpu_counter_alloc() behind NETFILTER_XTABLES_LEGACY. Let NETFILTER_XTABLES_LEGACY depend on !PREEMPT_RT. This will break selftest expecing the legacy options enabled and will be addressed in a following patch. Co-developed-by: Florian Westphal <fw@strlen.de> Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-07-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-0/+5
Cross-merge networking fixes after downstream PR (net-6.16-rc8). Conflicts: drivers/net/ethernet/microsoft/mana/gdma_main.c 9669ddda18fb ("net: mana: Fix warnings for missing export.h header inclusion") 755391121038 ("net: mana: Allocate MSI-X vectors dynamically") https://lore.kernel.org/20250711130752.23023d98@canb.auug.org.au Adjacent changes: drivers/net/ethernet/ti/icssg/icssg_prueth.h 6e86fb73de0f ("net: ti: icssg-prueth: Fix buffer allocation for ICSSG") ffe8a4909176 ("net: ti: icssg-prueth: Read firmware-names from device tree") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-24Merge tag 'ipsec-2025-07-23' of ↵Paolo Abeni2-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2025-07-23 1) Premption fixes for xfrm_state_find. From Sabrina Dubroca. 2) Initialize offload path also for SW IPsec GRO. This fixes a performance regression on SW IPsec offload. From Leon Romanovsky. 3) Fix IPsec UDP GRO for IKE packets. From Tobias Brunner, 4) Fix transport header setting for IPcomp after decompressing. From Fernando Fernandez Mancera. 5) Fix use-after-free when xfrmi_changelink tries to change collect_md for a xfrm interface. From Eyal Birger . 6) Delete the special IPcomp x->tunnel state along with the state x to avoid refcount problems. From Sabrina Dubroca. Please pull or let me know if there are problems. * tag 'ipsec-2025-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: Revert "xfrm: destroy xfrm_state synchronously on net exit path" xfrm: delete x->tunnel as we delete x xfrm: interface: fix use-after-free after changing collect_md xfrm interface xfrm: ipcomp: adjust transport header after decompressing xfrm: Set transport header to fix UDP GRO handling xfrm: always initialize offload path xfrm: state: use a consistent pcpu_id in xfrm_state_find xfrm: state: initialize state_ptrs earlier in xfrm_state_find ==================== Link: https://patch.msgid.link/20250723075417.3432644-1-steffen.klassert@secunet.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-07-22tcp: do not increment BeyondWindow MIB for old seqPaolo Abeni1-1/+5
The mentioned MIB is currently incremented even when a packet with an old sequence number (i.e. a zero window probe) is received, which is IMHO misleading. Explicitly restrict such MIB increment at the relevant events. Fixes: 6c758062c64d ("tcp: add LINUX_MIB_BEYOND_WINDOW") Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/20d147292eb4b13b6535e0ad6f56be64d9c330d3.1753118029.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-22tcp: do not set a zero size receive bufferPaolo Abeni1-0/+4
The nipa CI is reporting frequent failures in the mptcp_connect self-tests. In the failing scenarios (TCP -> MPTCP) the involved sockets are actually plain TCP ones, as fallback for passive socket at 2whs time cause the MPTCP listener to actually create a TCP socket. The transfer is stuck due to the receiver buffer being zero. With the stronger check in place, tcp_clamp_window() can be invoked while the TCP socket has sk_rmem_alloc == 0, and the receive buffer will be zeroed, too. Check for the critical condition in tcp_prune_queue() and just drop the packet without shrinking the receiver buffer. Fixes: 1d2fbaad7cd8 ("tcp: stronger sk_rcvbuf checks") Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20c18165d3f848e1c5c1b782d88c1a5ab38b3f70.1753118029.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-22tcp: trace retransmit failures in tcp_retransmit_skbFan Yu1-17/+29
Background ========== When TCP retransmits a packet due to missing ACKs, the retransmission may fail for various reasons (e.g., packets stuck in driver queues, receiver zero windows, or routing issues). The original tcp_retransmit_skb tracepoint: 'commit e086101b150a ("tcp: add a tracepoint for tcp retransmission")' lacks visibility into these failure causes, making production diagnostics difficult. Solution ======== Adds the retval("err") to the tcp_retransmit_skb tracepoint. Enables users to know why some tcp retransmission failed and users can filter retransmission failures by retval. Compatibility description ========================= This patch extends the tcp_retransmit_skb tracepoint by adding a new "err" field at the end of its existing structure (within TP_STRUCT__entry). The compatibility implications are detailed as follows: 1) Structural compatibility for legacy user-space tools Legacy tools/BPF programs accessing existing fields (by offset or name) can still work without modification or recompilation.The new field is appended to the end, preserving original memory layout. 2) Note: semantic changes The original tracepoint primarily only focused on successfully retransmitted packets. With this patch, the tracepoint now can figure out packets that may terminate early due to specific reasons. For accurate statistics, users should filter using "err" to distinguish outcomes. Before patched: field:const void * skbaddr; offset:8; size:8; signed:0; field:const void * skaddr; offset:16; size:8; signed:0; field:int state; offset:24; size:4; signed:1; field:__u16 sport; offset:28; size:2; signed:0; field:__u16 dport; offset:30; size:2; signed:0; field:__u16 family; offset:32; size:2; signed:0; field:__u8 saddr[4]; offset:34; size:4; signed:0; field:__u8 daddr[4]; offset:38; size:4; signed:0; field:__u8 saddr_v6[16]; offset:42; size:16; signed:0; field:__u8 daddr_v6[16]; offset:58; size:16; signed:0; print fmt: "skbaddr=%p skaddr=%p family=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c state=%s" After patched: field:const void * skbaddr; offset:8; size:8; signed:0; field:const void * skaddr; offset:16; size:8; signed:0; field:int state; offset:24; size:4; signed:1; field:__u16 sport; offset:28; size:2; signed:0; field:__u16 dport; offset:30; size:2; signed:0; field:__u16 family; offset:32; size:2; signed:0; field:__u8 saddr[4]; offset:34; size:4; signed:0; field:__u8 daddr[4]; offset:38; size:4; signed:0; field:__u8 saddr_v6[16]; offset:42; size:16; signed:0; field:__u8 daddr_v6[16]; offset:58; size:16; signed:0; field:int err; offset:76; size:4; signed:1; print fmt: "skbaddr=%p skaddr=%p family=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c state=%s err=%d" Co-developed-by: xu xin <xu.xin16@zte.com.cn> Signed-off-by: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Fan Yu <fan.yu9@zte.com.cn> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250721111607626_BDnIJB0ywk6FghN63bor@zte.com.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-21tcp: add tcp_sock_set_maxsegGeliang Tang1-9/+14
Add a helper tcp_sock_set_maxseg() to directly set the TCP_MAXSEG sockopt from kernel space. This new helper will be used in the following patch from MPTCP. Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250719-net-next-mptcp-tcp_maxseg-v2-2-8c910fbc5307@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-18net: s/dev_get_flags/netif_get_flags/Stanislav Fomichev3-3/+3
Commit cc34acd577f1 ("docs: net: document new locking reality") introduced netif_ vs dev_ function semantics: the former expects locked netdev, the latter takes care of the locking. We don't strictly follow this semantics on either side, but there are more dev_xxx handlers now that don't fit. Rename them to netif_xxx where appropriate. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250717172333.1288349-6-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-18net: s/dev_get_port_parent_id/netif_get_port_parent_id/Stanislav Fomichev1-1/+1
Commit cc34acd577f1 ("docs: net: document new locking reality") introduced netif_ vs dev_ function semantics: the former expects locked netdev, the latter takes care of the locking. We don't strictly follow this semantics on either side, but there are more dev_xxx handlers now that don't fit. Rename them to netif_xxx where appropriate. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250717172333.1288349-2-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-18net: track pfmemalloc drops via SKB_DROP_REASON_PFMEMALLOCJesper Dangaard Brouer2-15/+17
Add a new SKB drop reason (SKB_DROP_REASON_PFMEMALLOC) to track packets dropped due to memory pressure. In production environments, we've observed memory exhaustion reported by memory layer stack traces, but these drops were not properly tracked in the SKB drop reason infrastructure. While most network code paths now properly report pfmemalloc drops, some protocol-specific socket implementations still use sk_filter() without drop reason tracking: - Bluetooth L2CAP sockets - CAIF sockets - IUCV sockets - Netlink sockets - SCTP sockets - Unix domain sockets These remaining cases represent less common paths and could be converted in a follow-up patch if needed. The current implementation provides significantly improved observability into memory pressure events in the network stack, especially for key protocols like TCP and UDP, helping to diagnose problems in production environments. Reported-by: Matt Fleming <mfleming@cloudflare.com> Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org> Link: https://patch.msgid.link/175268316579.2407873.11634752355644843509.stgit@firesoul Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17Merge tag 'for-netdev' of ↵Jakub Kicinski1-69/+200
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Martin KaFai Lau says: ==================== pull-request: bpf-next 2025-07-17 We've added 13 non-merge commits during the last 20 day(s) which contain a total of 4 files changed, 712 insertions(+), 84 deletions(-). The main changes are: 1) Avoid skipping or repeating a sk when using a TCP bpf_iter, from Jordan Rife. 2) Clarify the driver requirement on using the XDP metadata, from Song Yoong Siang * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: doc: xdp: Clarify driver implementation for XDP Rx metadata selftests/bpf: Add tests for bucket resume logic in established sockets selftests/bpf: Create iter_tcp_destroy test program selftests/bpf: Create established sockets in socket iterator tests selftests/bpf: Make ehash buckets configurable in socket iterator tests selftests/bpf: Allow for iteration over multiple states selftests/bpf: Allow for iteration over multiple ports selftests/bpf: Add tests for bucket resume logic in listening sockets bpf: tcp: Avoid socket skips and repeats during iteration bpf: tcp: Use bpf_tcp_iter_batch_item for bpf_tcp_iter_state batch items bpf: tcp: Get rid of st_bucket_done bpf: tcp: Make sure iter->batch always contains a full bucket snapshot bpf: tcp: Make mem flags configurable through bpf_iter_tcp_realloc_batch ==================== Link: https://patch.msgid.link/20250717191731.4142326-1-martin.lau@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17neighbour: Update pneigh_entry in pneigh_create().Kuniyuki Iwashima1-3/+1
neigh_add() updates pneigh_entry() found or created by pneigh_create(). This update is serialised by RTNL, but we will remove it. Let's move the update part to pneigh_create() and make it return errno instead of a pointer of pneigh_entry. Now, the pneigh code is RTNL free. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250716221221.442239-16-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17neighbour: Split pneigh_lookup().Kuniyuki Iwashima1-2/+2
pneigh_lookup() has ASSERT_RTNL() in the middle of the function, which is confusing. When called with the last argument, creat, 0, pneigh_lookup() literally looks up a proxy neighbour entry. This is the case of the reader path as the fast path and RTM_GETNEIGH. pneigh_lookup(), however, creates a pneigh_entry when called with creat 1 from RTM_NEWNEIGH and SIOCSARP, which require RTNL. Let's split pneigh_lookup() into two functions. We will convert all the reader paths to RCU, and read_lock_bh(&tbl->lock) in the new pneigh_lookup() will be dropped. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250716221221.442239-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2-0/+2
Cross-merge networking fixes after downstream PR (net-6.16-rc7). Conflicts: Documentation/netlink/specs/ovpn.yaml 880d43ca9aa4 ("netlink: specs: clean up spaces in brackets") af52020fc599 ("ovpn: reject unexpected netlink attributes") drivers/net/phy/phy_device.c a44312d58e78 ("net: phy: Don't register LEDs for genphy") f0f2b992d818 ("net: phy: Don't register LEDs for genphy") https://lore.kernel.org/20250710114926.7ec3a64f@kernel.org drivers/net/wireless/intel/iwlwifi/fw/regulatory.c drivers/net/wireless/intel/iwlwifi/mld/regulatory.c 5fde0fcbd760 ("wifi: iwlwifi: mask reserved bits in chan_state_active_bitmap") ea045a0de3b9 ("wifi: iwlwifi: add support for accepting raw DSM tables by firmware") net/ipv6/mcast.c ae3264a25a46 ("ipv6: mcast: Delay put pmc->idev in mld_del_delrec()") a8594c956cc9 ("ipv6: mcast: Avoid a duplicate pointer check in mld_del_delrec()") https://lore.kernel.org/8cc52891-3653-4b03-a45e-05464fe495cf@kernel.org No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17net: fix segmentation after TCP/UDP fraglist GROFelix Fietkau2-0/+2
Since "net: gro: use cb instead of skb->network_header", the skb network header is no longer set in the GRO path. This breaks fraglist segmentation, which relies on ip_hdr()/tcp_hdr() to check for address/port changes. Fix this regression by selectively setting the network header for merged segment skbs. Fixes: 186b1ea73ad8 ("net: gro: use cb instead of skb->network_header") Signed-off-by: Felix Fietkau <nbd@nbd.name> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250705150622.10699-1-nbd@nbd.name Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-07-16tcp: fix UaF in tcp_prune_ofo_queue()Paolo Abeni1-1/+1
The CI reported a UaF in tcp_prune_ofo_queue(): BUG: KASAN: slab-use-after-free in tcp_prune_ofo_queue+0x55d/0x660 Read of size 4 at addr ffff8880134729d8 by task socat/20348 CPU: 0 UID: 0 PID: 20348 Comm: socat Not tainted 6.16.0-rc5-virtme #1 PREEMPT(full) Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x82/0xd0 print_address_description.constprop.0+0x2c/0x400 print_report+0xb4/0x270 kasan_report+0xca/0x100 tcp_prune_ofo_queue+0x55d/0x660 tcp_try_rmem_schedule+0x855/0x12e0 tcp_data_queue+0x4dd/0x2260 tcp_rcv_established+0x5e8/0x2370 tcp_v4_do_rcv+0x4ba/0x8c0 __release_sock+0x27a/0x390 release_sock+0x53/0x1d0 tcp_sendmsg+0x37/0x50 sock_write_iter+0x3c1/0x520 vfs_write+0xc09/0x1210 ksys_write+0x183/0x1d0 do_syscall_64+0xc1/0x380 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf73ef2337 Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 RSP: 002b:00007ffd4f924708 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf73ef2337 RDX: 0000000000002000 RSI: 0000555f11d1a000 RDI: 0000000000000008 RBP: 0000555f11d1a000 R08: 0000000000002000 R09: 0000000000000000 R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000008 R13: 0000000000002000 R14: 0000555ee1a44570 R15: 0000000000002000 </TASK> Allocated by task 20348: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc_node_noprof+0x110/0x340 __alloc_skb+0x213/0x2e0 tcp_collapse+0x43f/0xff0 tcp_try_rmem_schedule+0x6b9/0x12e0 tcp_data_queue+0x4dd/0x2260 tcp_rcv_established+0x5e8/0x2370 tcp_v4_do_rcv+0x4ba/0x8c0 __release_sock+0x27a/0x390 release_sock+0x53/0x1d0 tcp_sendmsg+0x37/0x50 sock_write_iter+0x3c1/0x520 vfs_write+0xc09/0x1210 ksys_write+0x183/0x1d0 do_syscall_64+0xc1/0x380 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 20348: kasan_save_stack+0x24/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x38/0x50 kmem_cache_free+0x149/0x330 tcp_prune_ofo_queue+0x211/0x660 tcp_try_rmem_schedule+0x855/0x12e0 tcp_data_queue+0x4dd/0x2260 tcp_rcv_established+0x5e8/0x2370 tcp_v4_do_rcv+0x4ba/0x8c0 __release_sock+0x27a/0x390 release_sock+0x53/0x1d0 tcp_sendmsg+0x37/0x50 sock_write_iter+0x3c1/0x520 vfs_write+0xc09/0x1210 ksys_write+0x183/0x1d0 do_syscall_64+0xc1/0x380 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888013472900 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 216 bytes inside of freed 232-byte region [ffff888013472900, ffff8880134729e8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13472 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88800198fb40 ffffea0000347b10 ffffea00004f5290 raw: 0000000000000000 0000000000120012 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88800198fb40 ffffea0000347b10 ffffea00004f5290 head: 0000000000000000 0000000000120012 00000000f5000000 0000000000000000 head: 0080000000000001 ffffea00004d1c81 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888013472880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888013472900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888013472980: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ^ ffff888013472a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888013472a80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb Indeed tcp_prune_ofo_queue() is reusing the skb dropped a few lines above. The caller wants to enqueue 'in_skb', lets check space vs the latter. Fixes: 1d2fbaad7cd8 ("tcp: stronger sk_rcvbuf checks") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Tested-by: syzbot+865aca08c0533171bf6a@syzkaller.appspotmail.com Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/b78d2d9bdccca29021eed9a0e7097dd8dc00f485.1752567053.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-14tcp: stronger sk_rcvbuf checksEric Dumazet1-6/+16
Currently, TCP stack accepts incoming packet if sizes of receive queues are below sk->sk_rcvbuf limit. This can cause memory overshoot if the packet is big, like an 1/2 MB BIG TCP one. Refine the check to take into account the incoming skb truesize. Note that we still accept the packet if the receive queue is empty, to not completely freeze TCP flows in pathological conditions. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250711114006.480026-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-14tcp: add const to tcp_try_rmem_schedule() and sk_rmem_schedule() skbEric Dumazet1-1/+1
These functions to not modify the skb, add a const qualifier. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250711114006.480026-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-14tcp: call tcp_measure_rcv_mss() for ooo packetsEric Dumazet1-0/+1
tcp_measure_rcv_mss() is used to update icsk->icsk_ack.rcv_mss (tcpi_rcv_mss in tcp_info) and tp->scaling_ratio. Calling it from tcp_data_queue_ofo() makes sure these fields are updated, and permits a better tuning of sk->sk_rcvbuf, in the case a new flow receives many ooo packets. Fixes: dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250711114006.480026-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-14tcp: add LINUX_MIB_BEYOND_WINDOWEric Dumazet2-0/+2
Add a new SNMP MIB : LINUX_MIB_BEYOND_WINDOW Incremented when an incoming packet is received beyond the receiver window. nstat -az | grep TcpExtBeyondWindow Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250711114006.480026-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-14tcp: do not accept packets beyond windowEric Dumazet1-5/+17
Currently, TCP accepts incoming packets which might go beyond the offered RWIN. Add to tcp_sequence() the validation of packet end sequence. Add the corresponding check in the fast path. We relax this new constraint if the receive queue is empty, to not freeze flows from buggy peers. Add a new drop reason : SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250711114006.480026-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-14net: ipv4: fix incorrect MTU in broadcast routesOscar Maes1-1/+0
Currently, __mkroute_output overrules the MTU value configured for broadcast routes. This buggy behaviour can be reproduced with: ip link set dev eth1 mtu 9000 ip route del broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2 ip route add broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2 mtu 1500 The maximum packet size should be 1500, but it is actually 8000: ping -b 192.168.0.255 -s 8000 Fix __mkroute_output to allow MTU values to be configured for for broadcast routes (to support a mixed-MTU local-area-network). Signed-off-by: Oscar Maes <oscmaes92@gmail.com> Link: https://patch.msgid.link/20250710142714.12986-1-oscmaes92@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>