From 9997d5dd177c52017fa0541bf236a4232c8148e6 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 12 Apr 2023 09:50:08 -0300 Subject: [PATCH] perf trace: 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 --- tools/perf/builtin-trace.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 72ef0bebb06b..8ee3a45c3c54 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -2288,7 +2288,7 @@ static void syscall__exit(struct syscall *sc) if (!sc) return; - free(sc->arg_fmt); + zfree(&sc->arg_fmt); } static int trace__sys_enter(struct trace *trace, struct evsel *evsel, @@ -3124,7 +3124,7 @@ static void evlist__free_syscall_tp_fields(struct evlist *evlist) if (!et || !evsel->tp_format || strcmp(evsel->tp_format->system, "syscalls")) continue; - free(et->fmt); + zfree(&et->fmt); free(et); } } @@ -4670,11 +4670,11 @@ static void trace__exit(struct trace *trace) int i; strlist__delete(trace->ev_qualifier); - free(trace->ev_qualifier_ids.entries); + zfree(&trace->ev_qualifier_ids.entries); if (trace->syscalls.table) { for (i = 0; i <= trace->sctbl->syscalls.max_id; i++) syscall__exit(&trace->syscalls.table[i]); - free(trace->syscalls.table); + zfree(&trace->syscalls.table); } syscalltbl__delete(trace->sctbl); zfree(&trace->perfconfig_events);