From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 7 Mar 2025 21:23:09 +0000 (-0600)
Subject: Assert that wrapper_handler()'s argument is within expected range.
X-Git-Tag: REL_18_BETA1~651
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=088f8e2d568eaa963fe68a15287002081314fad8;p=thirdparty%2Fpostgresql.git

Assert that wrapper_handler()'s argument is within expected range.

pqsignal() already does a similar check, but strange Valgrind
reports have us wondering if wrapper_handler() is somehow getting
called with an invalid signal number.

Reported-by: Tomas Vondra <tomas@vondra.me>
Suggested-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/ace01111-f9ac-4f61-b1b1-8e9379415444%40vondra.me
Backpatch-through: 17
---

diff --git a/src/port/pqsignal.c b/src/port/pqsignal.c
index 5dd8b76bae8..26943845e21 100644
--- a/src/port/pqsignal.c
+++ b/src/port/pqsignal.c
@@ -87,6 +87,9 @@ wrapper_handler(SIGNAL_ARGS)
 {
 	int			save_errno = errno;
 
+	Assert(postgres_signal_arg > 0);
+	Assert(postgres_signal_arg < PG_NSIG);
+
 #ifndef FRONTEND
 
 	/*
@@ -123,6 +126,7 @@ pqsignal(int signo, pqsigfunc func)
 	struct sigaction act;
 #endif
 
+	Assert(signo > 0);
 	Assert(signo < PG_NSIG);
 
 	if (func != SIG_IGN && func != SIG_DFL)