Re: [PATCH] perf util: Fix use after free in metric__new

[Ian Rogers]

On Wed, Dec 8, 2021 at 9:11 AM José Expósito <jose.exposito89@xxxxxxxxx> wrote:
>
> Addresses-Coverity-ID: 1494000
> Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx>

Acked-by: Ian Rogers <irogers@google,com>

This can only happen in the ENOMEM case, but it is a good fix.

Fixes: b85a4d61d302 (perf metric: Allow modifiers on metrics)

Thanks,
Ian

> ---
>  tools/perf/util/metricgroup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index fffe02aae3ed..4d2fed3aefd1 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -209,8 +209,8 @@ static struct metric *metric__new(const struct pmu_event *pe,
>         m->metric_name = pe->metric_name;
>         m->modifier = modifier ? strdup(modifier) : NULL;
>         if (modifier && !m->modifier) {
> -               free(m);
>                 expr__ctx_free(m->pctx);
> +               free(m);
>                 return NULL;
>         }
>         m->metric_expr = pe->metric_expr;
> --
> 2.25.1
>