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* [PATCH] perf parse-events: fix 3 use after frees
@ 2020-03-13 23:02 Ian Rogers
  2020-03-14 13:59 ` Jiri Olsa
  0 siblings, 1 reply; 3+ messages in thread
From: Ian Rogers @ 2020-03-13 23:02 UTC (permalink / raw)
  To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Mark Rutland, Alexander Shishkin, Jiri Olsa, Namhyung Kim,
	Andi Kleen, Adrian Hunter, Leo Yan, linux-kernel,
	clang-built-linux
  Cc: Stephane Eranian, Ian Rogers

Reproducible with a clang asan build and then running perf test in
particular 'Parse event definition strings'.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/parse-events.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

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


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] perf parse-events: fix 3 use after frees
  2020-03-13 23:02 [PATCH] perf parse-events: fix 3 use after frees Ian Rogers
@ 2020-03-14 13:59 ` Jiri Olsa
  2020-03-14 16:54   ` Ian Rogers
  0 siblings, 1 reply; 3+ messages in thread
From: Jiri Olsa @ 2020-03-14 13:59 UTC (permalink / raw)
  To: Ian Rogers
  Cc: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Mark Rutland, Alexander Shishkin, Namhyung Kim, Andi Kleen,
	Adrian Hunter, Leo Yan, linux-kernel, clang-built-linux,
	Stephane Eranian

On Fri, Mar 13, 2020 at 04:02:49PM -0700, Ian Rogers wrote:
> Reproducible with a clang asan build and then running perf test in
> particular 'Parse event definition strings'.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/parse-events.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> 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;

so it's pmu->name pointer.. does pmu get destroyed before the evsel?
also should we free that then like below?

>  		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,

nice catch ;-)

>  						 pmu->name, alias->str);
>  					ok++;
>  				}
> -- 
> 2.25.1.481.gfbce0eb801-goog
> 

thanks,
jirka


---
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);
 }
 


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] perf parse-events: fix 3 use after frees
  2020-03-14 13:59 ` Jiri Olsa
@ 2020-03-14 16:54   ` Ian Rogers
  0 siblings, 0 replies; 3+ messages in thread
From: Ian Rogers @ 2020-03-14 16:54 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
	Mark Rutland, Alexander Shishkin, Namhyung Kim, Andi Kleen,
	Adrian Hunter, Leo Yan, LKML, clang-built-linux,
	Stephane Eranian

On Sat, Mar 14, 2020 at 6:59 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Fri, Mar 13, 2020 at 04:02:49PM -0700, Ian Rogers wrote:
> > Reproducible with a clang asan build and then running perf test in
> > particular 'Parse event definition strings'.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> >  tools/perf/util/parse-events.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > 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;
>
> so it's pmu->name pointer.. does pmu get destroyed before the evsel?
> also should we free that then like below?
>
> >               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,
>
> nice catch ;-)
>
> >                                                pmu->name, alias->str);
> >                                       ok++;
> >                               }
> > --
> > 2.25.1.481.gfbce0eb801-goog
> >
>
> thanks,
> jirka
>
>
> ---
> 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);
>  }

Agreed on the zfree! I'll upload a v2 with it. I've tested with
address sanitizer in case of double frees, etc. I haven't yet fuzz
tested the latest version of parse events, libfuzz detects memory
leaks between iterations so I expect there will be future small
patches like this coming.

Thanks,
Ian

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2020-03-13 23:02 [PATCH] perf parse-events: fix 3 use after frees Ian Rogers
2020-03-14 13:59 ` Jiri Olsa
2020-03-14 16:54   ` Ian Rogers

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