From: William Lallemand <wlallemand@haproxy.org>
Date: Wed, 7 Dec 2022 14:21:24 +0000 (+0100)
Subject: BUG/MEDIUM: mworker: fix segv in early failure of mworker mode with peers
X-Git-Tag: v2.8-dev1~170
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=035058e8bfe4fc731b2ede8fcdc2b8d14c4936ce;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: mworker: fix segv in early failure of mworker mode with peers

During an early failure of the mworker mode, the
mworker_cleanlisteners() function is called and tries to cleanup the
peers, however the peers are in a semi-initialized state and will use
NULL pointers.

The fix check the variable before trying to use them.

Bug revealed in issue #1956.

Could be backported as far as 2.0.
---

diff --git a/src/mworker.c b/src/mworker.c
index fc4dee104c..90e96158db 100644
--- a/src/mworker.c
+++ b/src/mworker.c
@@ -467,8 +467,10 @@ void mworker_cleanlisteners()
 
 		stop_proxy(curpeers->peers_fe);
 		/* disable this peer section so that it kills itself */
-		signal_unregister_handler(curpeers->sighandler);
-		task_destroy(curpeers->sync_task);
+		if (curpeers->sighandler)
+			signal_unregister_handler(curpeers->sighandler);
+		if (curpeers->sync_task)
+			task_destroy(curpeers->sync_task);
 		curpeers->sync_task = NULL;
 		task_destroy(curpeers->peers_fe->task);
 		curpeers->peers_fe->task = NULL;