From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Wed, 12 Apr 2023 12:50:08 +0000 (-0300)
Subject: perf evlist: Use zfree() to reduce chances of use after free
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2bfc8134f95852bd8b0190641c2d2b059cb1c8cc;p=linux.git

perf evlist: Use zfree() to reduce chances of use after free

Do defensive programming by using zfree() to initialize freed pointers
to NULL, so that eventual use after free result in a NULL pointer deref
instead of more subtle behaviour.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index df6af38ca22e0..2260e27adf44c 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -2325,7 +2325,7 @@ int evlist__parse_event_enable_time(struct evlist *evlist, struct record_opts *o
 close_timerfd:
 	close(eet->timerfd);
 free_eet_times:
-	free(eet->times);
+	zfree(&eet->times);
 free_eet:
 	free(eet);
 	return err;
@@ -2407,7 +2407,7 @@ void event_enable_timer__exit(struct event_enable_timer **ep)
 {
 	if (!ep || !*ep)
 		return;
-	free((*ep)->times);
+	zfree(&(*ep)->times);
 	zfree(ep);
 }