Fix memory leak while attempting to connect to backend.

If no backend is up and running, memory for copy of startup packet
will be lost. This was brought by commit cdb49d3b7. Per coverity.

diff --git a/src/protocol/child.c b/src/protocol/child.c
index 59e1e7fd1f7ccb1f4d708bfb5311d17543857742..4da2914b00cc49ba6a00c8fd9e30e6772f511d82 100644 (file)
--- a/src/protocol/child.c
+++ b/src/protocol/child.c
@@ -910,8 +910,9 @@ static StartupPacket *StartupPacketCopy(StartupPacket *sp)
 static POOL_CONNECTION_POOL *connect_backend(StartupPacket *sp, POOL_CONNECTION *frontend)
 {
        POOL_CONNECTION_POOL *backend;
-       StartupPacket *topmem_sp;
-       int i;
+       StartupPacket *volatile topmem_sp = NULL;
+       volatile bool   topmem_sp_set = false;
+       int                     i;
 
        /* connect to the backend */
        backend = pool_create_cp();
@@ -948,6 +949,7 @@ static POOL_CONNECTION_POOL *connect_backend(StartupPacket *sp, POOL_CONNECTION
                                 * save startup packet info
                                 */
                                CONNECTION_SLOT(backend, i)->sp = topmem_sp;
+                               topmem_sp_set = true;
 
                                /* send startup packet */
                                send_startup_packet(CONNECTION_SLOT(backend, i));
@@ -961,10 +963,17 @@ static POOL_CONNECTION_POOL *connect_backend(StartupPacket *sp, POOL_CONNECTION
        PG_CATCH();
        {
                pool_discard_cp(sp->user, sp->database, sp->major);
+               topmem_sp = NULL;
                PG_RE_THROW();
        }
        PG_END_TRY();
 
+       /* At this point, we need to free previously allocated memory for the
+        * startup packet if no backend is up.
+        */
+       if (!topmem_sp_set && topmem_sp != NULL)
+               pfree(topmem_sp);
+
        return backend;
 }