From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Wed, 12 Apr 2023 12:50:08 +0000 (-0300)
Subject: perf list: Use zfree() to reduce chances of use after free
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b20c63084eb2c591006109aefbdeb3cad7a57d23;p=linux.git

perf list: 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/builtin-list.c b/tools/perf/builtin-list.c
index 29f09cefed886..1f5dbd5f0ba48 100644
--- a/tools/perf/builtin-list.c
+++ b/tools/perf/builtin-list.c
@@ -127,7 +127,7 @@ static void default_print_event(void *ps, const char *pmu_name, const char *topi
 	if (strcmp(print_state->last_topic, topic ?: "")) {
 		if (topic)
 			printf("\n%s:\n", topic);
-		free(print_state->last_topic);
+		zfree(&print_state->last_topic);
 		print_state->last_topic = strdup(topic ?: "");
 	}
 
@@ -197,7 +197,7 @@ static void default_print_metric(void *ps,
 			else
 				printf("%s\n", group);
 		}
-		free(print_state->last_metricgroups);
+		zfree(&print_state->last_metricgroups);
 		print_state->last_metricgroups = strdup(group ?: "");
 	}
 	if (!print_state->metrics)