[PATCH 1/1] perf kwork: Use zfree() to avoid possibly accessing dangling pointers

From: arnaldo . melo
Date: Mon May 06 2024 - 23:16:03 EST


When freeing a->b it is good practice to set a->b to NULL using
zfree(&a->b) so that when we have a bug where a reference to a freed 'a'
pointer is kept somewhere, we can more quickly cause a segfault if some
code tries to use a->b.

Convert one such case in the 'perf kwork' codebase.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Yang Jihong <yangjihong1@xxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-kwork.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-kwork.c b/tools/perf/builtin-kwork.c
index 0092b9b39611d7e9..56e3f3a5e03a2d66 100644
--- a/tools/perf/builtin-kwork.c
+++ b/tools/perf/builtin-kwork.c
@@ -2230,7 +2230,7 @@ static int perf_kwork__top(struct perf_kwork *kwork)
perf_kwork__top_report(kwork);

out:
- free(kwork->top_stat.cpus_runtime);
+ zfree(&kwork->top_stat.cpus_runtime);
return ret;
}

--
2.44.0