From: Tatsuo Ishii <ishii@postgresql.org>
Date: Mon, 22 Jul 2024 10:32:41 +0000 (+0900)
Subject: Fix another segmentation fault.
X-Git-Tag: V4_4_8~12
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=c1dd550d38c89f4e67d2a1f9ca1e1fd169cee7b9;p=pgpool2.git

Fix another segmentation fault.

It is reported that pgpool child segfaulted in pool_do_auth. The cause
was MAIN_CONNECTION() returns NULL. It seems my_main_node_id was set
to incorrect node id 0, which was actually in down status. thus there
was no connection in cp->slots[0]. In this particular case a client
connected to pgpool while failover occurred in another pgpool node,
and it was propagated by watchdog, which changed backend_status in
shared memory. new_connection() properly updates my_backend_status but
it forgot to update my_main_node_id, and MAIN_CONNECTION returned
incorrect backend id.

Problem reported by: Emond Papegaaij
Discussion: [pgpool-general: 9175] Segmentation fault
https://www.pgpool.net/pipermail/pgpool-general/2024-July/001852.html
Backpatch-through: V4.1.
---

diff --git a/src/protocol/pool_connection_pool.c b/src/protocol/pool_connection_pool.c
index 3adbc0eab..a3bfc5f11 100644
--- a/src/protocol/pool_connection_pool.c
+++ b/src/protocol/pool_connection_pool.c
@@ -5,7 +5,7 @@
  * pgpool: a language independent connection pool server for PostgreSQL
  * written by Tatsuo Ishii
  *
- * Copyright (c) 2003-2020	PgPool Global Development Group
+ * Copyright (c) 2003-2024	PgPool Global Development Group
  *
  * Permission to use, copy, modify, and distribute this software and
  * its documentation for any purpose and without fee is hereby
@@ -911,6 +911,7 @@ static POOL_CONNECTION_POOL * new_connection(POOL_CONNECTION_POOL * p)
 
 			/* sync local status with global status */
 			*(my_backend_status[i]) = status;
+			my_main_node_id = Req_info->main_node_id;
 			continue;
 		}