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 d91b011cfbf950b6c16ba7652d916519c4979d49..ca021febd5889987b466f14a66d4eaccc8100529 100644 (file)
--- a/src/protocol/child.c
+++ b/src/protocol/child.c
@@ -916,8 +916,9 @@ 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();
@@ -954,6 +955,7 @@ 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));
@@ -967,10 +969,17 @@ 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;
 }