diff options
| author | David Howells <dhowells@redhat.com> | 2025-12-02 16:24:53 +0000 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2025-12-05 17:09:28 -0600 |
| commit | 9d85ac939d52e93d80efb01a299c6f0bedb30487 (patch) | |
| tree | 2d3f8f8a1931ddcbcd8241110ff53afb9e4e2c6a /fs | |
| parent | 1ef15fbe6771119dc1d3bd4ed201100cfacb842e (diff) | |
| download | tip-9d85ac939d52e93d80efb01a299c6f0bedb30487.tar.gz | |
cifs: Fix handling of a beyond-EOF DIO/unbuffered read over SMB1
If a DIO read or an unbuffered read request extends beyond the EOF, the
server will return a short read and a status code indicating that EOF was
hit, which gets translated to -ENODATA. Note that the client does not cap
the request at i_size, but asks for the amount requested in case there's a
race on the server with a third party.
Now, on the client side, the request will get split into multiple
subrequests if rsize is smaller than the full request size. A subrequest
that starts before or at the EOF and returns short data up to the EOF will
be correctly handled, with the NETFS_SREQ_HIT_EOF flag being set,
indicating to netfslib that we can't read more.
If a subrequest, however, starts after the EOF and not at it, HIT_EOF will
not be flagged, its error will be set to -ENODATA and it will be abandoned.
This will cause the request as a whole to fail with -ENODATA.
Fix this by setting NETFS_SREQ_HIT_EOF on any subrequest that lies beyond
the EOF marker.
This can be reproduced by mounting with "cache=none,sign,vers=1.0" and
doing a read of a file that's significantly bigger than the size of the
file (e.g. attempting to read 64KiB from a 16KiB file).
Fixes: a68c74865f51 ("cifs: Fix SMB1 readv/writev callback in the same way as SMB2/3")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/smb/client/cifssmb.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 428e582e0414f8..32aea71deab226 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -1374,7 +1374,7 @@ do_retry: } else { size_t trans = rdata->subreq.transferred + rdata->got_bytes; if (trans < rdata->subreq.len && - rdata->subreq.start + trans == ictx->remote_i_size) { + rdata->subreq.start + trans >= ictx->remote_i_size) { rdata->result = 0; __set_bit(NETFS_SREQ_HIT_EOF, &rdata->subreq.flags); } else if (rdata->got_bytes > 0) { |
