From: Gilad Benjamini <gilad@altornetworks.com>
Date: Wed, 21 Apr 2010 05:15:19 +0000 (-0400)
Subject: Clean up properly when adding a signal handler fails.
X-Git-Tag: release-2.0.5-beta~47
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b84b598eae8293dc02bf91cfb4f1cde9516f2fe0;p=libevent

Clean up properly when adding a signal handler fails.

Previously, when a signation() or signal() call failed, we would free
the element we added to sh_old, but not actually clear the pointer.
This would leave a dangling pointer in sh_old that could cause a
crash later.
---

diff --git a/signal.c b/signal.c
index be02f9d5..386f4763 100644
--- a/signal.c
+++ b/signal.c
@@ -185,12 +185,14 @@ _evsig_set_handler(struct event_base *base,
 	if (sigaction(evsignal, &sa, sig->sh_old[evsignal]) == -1) {
 		event_warn("sigaction");
 		mm_free(sig->sh_old[evsignal]);
+		sig->sh_old[evsignal] = NULL;
 		return (-1);
 	}
 #else
 	if ((sh = signal(evsignal, handler)) == SIG_ERR) {
 		event_warn("signal");
 		mm_free(sig->sh_old[evsignal]);
+		sig->sh_old[evsignal] = NULL;
 		return (-1);
 	}
 	*sig->sh_old[evsignal] = sh;