[PATCH 5.16 1002/1039] perf metricgroup: Fix use after free in metric__new()

From: Greg Kroah-Hartman
Date: Mon Jan 24 2022 - 21:01:51 EST


From: José Expósito <jose.exposito89@xxxxxxxxx>

commit e000ea0beffb5497425054b151369fe37a792ece upstream.

We shouldn't free() something that will be used in the next line, fix
it.

Fixes: b85a4d61d3022608 ("perf metric: Allow modifiers on metrics")
Addresses-Coverity-ID: 1494000
Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: John Garry <john.garry@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20211208171113.22089-1-jose.exposito89@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/util/metricgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -209,8 +209,8 @@ static struct metric *metric__new(const
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;