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

From: Arnaldo Carvalho de Melo
Date: Tue May 07 2024 - 10:59:32 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 probe' 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>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-probe.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 019fef8da6a8e60f..003a3bcebfdfc2d1 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -325,7 +325,7 @@ static void cleanup_params(void)
for (i = 0; i < params->nevents; i++)
clear_perf_probe_event(params->events + i);
line_range__clear(&params->line_range);
- free(params->target);
+ zfree(&params->target);
strfilter__delete(params->filter);
nsinfo__put(params->nsi);
zfree(&params);
--
2.44.0