[PATCH 5.10 16/36] perf auxtrace: Fix potential NULL pointer dereference

Greg Kroah-Hartman
2021-04-26T07:50:02Z

From: Leo Yan <leo.yan@linaro.org>

[ Upstream commit b14585d9f18dc617e975815570fe836be656b1da ]

In the function auxtrace_parse_snapshot_options(), the callback pointer
"itr->parse_snapshot_options" can be NULL if it has not been set during
the AUX record initialization. This can cause tool crashing if the
callback pointer "itr->parse_snapshot_options" is dereferenced without
performing NULL check.

Add a NULL check for the pointer "itr->parse_snapshot_options" before
invoke the callback.

Fixes: d20031bb63dd6dde ("perf tools: Add AUX area tracing Snapshot Mode")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: http://lore.kernel.org/lkml/20210420151554.2031768-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/auxtrace.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index d8ada6a3c555..d3c15b53495d 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -636,7 +636,7 @@ int auxtrace_parse_snapshot_options(struct auxtrace_record *itr,
break;
}

- if (itr)
+ if (itr && itr->parse_snapshot_options)
return itr->parse_snapshot_options(itr, opts, str);

pr_err("No AUX area tracing to snapshot\n");
--
2.30.2