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 aa76d5c56a81176160e512165f2164a3aaa65ab5..2473c969b8028035197e30d4d6cce52b998750f8 100644 (file)
--- a/src/protocol/child.c
+++ b/src/protocol/child.c
@@ -965,7 +965,8 @@ StartupPacketCopy(StartupPacket *sp)
 static POOL_CONNECTION_POOL * connect_backend(StartupPacket *sp, POOL_CONNECTION * frontend)
 {
        POOL_CONNECTION_POOL *backend;
-       StartupPacket *topmem_sp;
+       StartupPacket *volatile topmem_sp = NULL;
+       volatile bool   topmem_sp_set = false;
        int                     i;
 
        /* connect to the backend */
@@ -1005,6 +1006,7 @@ 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));
@@ -1028,10 +1030,17 @@ 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;
 }