Re: [PATCH v2] perf parse-events: fix 3 use after frees

From: Jiri Olsa
Date: Wed Mar 18 2020 - 06:28:42 EST


On Sat, Mar 14, 2020 at 10:03:56AM -0700, Ian Rogers wrote:
> Reproducible with a clang asan build and then running perf test in
> particular 'Parse event definition strings'.
>
> v2 frees the evsel->pmu_name avoiding a memory leak.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka

> ---
> tools/perf/util/evsel.c | 1 +
> tools/perf/util/parse-events.c | 6 +++---
> 2 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 816d930d774e..15ccd193483f 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -1287,6 +1287,7 @@ void perf_evsel__exit(struct evsel *evsel)
> perf_thread_map__put(evsel->core.threads);
> zfree(&evsel->group_name);
> zfree(&evsel->name);
> + zfree(&evsel->pmu_name);
> perf_evsel__object.fini(evsel);
> }
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index a14995835d85..593b6b03785d 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1449,7 +1449,7 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
> evsel = __add_event(list, &parse_state->idx, &attr, NULL, pmu, NULL,
> auto_merge_stats, NULL);
> if (evsel) {
> - evsel->pmu_name = name;
> + evsel->pmu_name = name ? strdup(name) : NULL;
> evsel->use_uncore_alias = use_uncore_alias;
> return 0;
> } else {
> @@ -1497,7 +1497,7 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
> evsel->snapshot = info.snapshot;
> evsel->metric_expr = info.metric_expr;
> evsel->metric_name = info.metric_name;
> - evsel->pmu_name = name;
> + evsel->pmu_name = name ? strdup(name) : NULL;
> evsel->use_uncore_alias = use_uncore_alias;
> evsel->percore = config_term_percore(&evsel->config_terms);
> }
> @@ -1547,7 +1547,7 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
> if (!parse_events_add_pmu(parse_state, list,
> pmu->name, head,
> true, true)) {
> - pr_debug("%s -> %s/%s/\n", config,
> + pr_debug("%s -> %s/%s/\n", str,
> pmu->name, alias->str);
> ok++;
> }
> --
> 2.25.1.481.gfbce0eb801-goog
>