[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <CAP-5=fV3T6G29Hrg3fGRnenjxUMjVfPK-zFGQgp9UgJn1JBA9g@mail.gmail.com>
Date: Wed, 8 May 2024 16:40:40 -0700
From: Ian Rogers <irogers@...gle.com>
To: arnaldo.melo@...il.com
Cc: Yang Jihong <yangjihong1@...wei.com>, Adrian Hunter <adrian.hunter@...el.com>,
Jiri Olsa <jolsa@...nel.org>, Kan Liang <kan.liang@...ux.intel.com>,
Namhyung Kim <namhyung@...nel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>, linux-perf-users@...r.kernel.org
Subject: Re: [PATCH 1/1] perf kwork: Use zfree() to avoid possibly accessing
dangling pointers
On Mon, May 6, 2024 at 8:15 PM <arnaldo.melo@...il.com> wrote:
>
> 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@...el.com>
> Cc: Ian Rogers <irogers@...gle.com>
> Cc: Jiri Olsa <jolsa@...nel.org>
> Cc: Kan Liang <kan.liang@...ux.intel.com>
> Cc: Namhyung Kim <namhyung@...nel.org>
> Cc: Yang Jihong <yangjihong1@...wei.com>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
Reviewed-by: Ian Rogers <irogers@...gle.com>
Thanks,
Ian
> ---
> 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
>
Powered by blists - more mailing lists