Re: [PATCH 1/1] perf probe: Free string returned by synthesize_perf_probe_point() on failure in synthesize_perf_probe_command()

From: Ian Rogers
Date: Thu Aug 10 2023 - 17:57:46 EST


On Fri, Aug 4, 2023 at 9:27 AM Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
>
> Building perf with EXTRA_CFLAGS="-fsanitize=address" a leak was detected
> elsewhere and lead to an audit, where we found that
> synthesize_perf_probe_command() may leak synthesize_perf_probe_point()
> return on failure, fix it.
>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Ian Rogers <irogers@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Link: https://lore.kernel.org/lkml/
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> ---
> tools/perf/util/probe-event.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index c7bfeab610a3679a..2835d87cb97771f9 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -2063,14 +2063,18 @@ char *synthesize_perf_probe_command(struct perf_probe_event *pev)
> goto out;
>
> tmp = synthesize_perf_probe_point(&pev->point);
> - if (!tmp || strbuf_addstr(&buf, tmp) < 0)
> + if (!tmp || strbuf_addstr(&buf, tmp) < 0) {
> + free(tmp);
> goto out;
> + }
> free(tmp);
>
> for (i = 0; i < pev->nargs; i++) {
> tmp = synthesize_perf_probe_arg(pev->args + i);
> - if (!tmp || strbuf_addf(&buf, " %s", tmp) < 0)
> + if (!tmp || strbuf_addf(&buf, " %s", tmp) < 0) {
> + free(tmp);
> goto out;
> + }
> free(tmp);
> }
>
> --
> 2.37.1
>