Messages in this thread | | | From | Ian Rogers <> | Date | Wed, 8 May 2024 23:43:15 -0700 | Subject | Re: [PATCH 1/1] perf probe: Use zfree() to avoid possibly accessing dangling pointers |
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On Tue, May 7, 2024 at 7:58 AM Arnaldo Carvalho de Melo <acme@kernel.org> 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 probe' codebase. > > Cc: Adrian Hunter <adrian.hunter@intel.com> > Cc: Ian Rogers <irogers@google.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Kan Liang <kan.liang@linux.intel.com> > Cc: Namhyung Kim <namhyung@kernel.org> > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > --- > tools/perf/builtin-probe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c > index 019fef8da6a8e60f..003a3bcebfdfc2d1 100644 > --- a/tools/perf/builtin-probe.c > +++ b/tools/perf/builtin-probe.c > @@ -325,7 +325,7 @@ static void cleanup_params(void) > for (i = 0; i < params->nevents; i++) > clear_perf_probe_event(params->events + i); > line_range__clear(¶ms->line_range); > - free(params->target); > + zfree(¶ms->target); > strfilter__delete(params->filter); > nsinfo__put(params->nsi); > zfree(¶ms);
The change is fine but params is freed here, so the potential to read "->target" is small.
Reviewed-by: Ian Rogers <irogers@google.com>
Thanks, Ian
> -- > 2.44.0 >
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