From: Chun-Tse Shao <ctshao@google.com>
Date: Mon, 3 Mar 2025 18:32:41 +0000 (-0800)
Subject: perf record: Fix a asan runtime error in util/maps.c
X-Git-Tag: v6.16-rc1~57^2~46
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8cdf00b843ea3ca0e920176937bbc906b0b5bb04;p=thirdparty%2Flinux.git

perf record: Fix a asan runtime error in util/maps.c

If I build perf with asan and run Zstd test:

  $ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=undefined"
  $ /tmp/perf/perf test "Zstd perf.data compression/decompression" -vv
   83: Zstd perf.data compression/decompression:
  ...
  util/maps.c:1046:5: runtime error: null pointer passed as argument 2, which is declared to never be null
  ...

The issue was caused by `bsearch`. The patch adds a check to ensure
argument 2 and 3 are not NULL and 0.

Testing with the commands above confirms that the runtime error is
resolved.

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250303183646.327510-2-ctshao@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
index 0b40d901675ed..85b2a93a59ac6 100644
--- a/tools/perf/util/maps.c
+++ b/tools/perf/util/maps.c
@@ -1082,10 +1082,13 @@ struct map *maps__find(struct maps *maps, u64 ip)
 	while (!done) {
 		down_read(maps__lock(maps));
 		if (maps__maps_by_address_sorted(maps)) {
-			struct map **mapp =
-				bsearch(&ip, maps__maps_by_address(maps), maps__nr_maps(maps),
-					sizeof(*mapp), map__addr_cmp);
+			struct map **mapp = NULL;
+			struct map **maps_by_address = maps__maps_by_address(maps);
+			unsigned int nr_maps = maps__nr_maps(maps);
 
+			if (maps_by_address && nr_maps)
+				mapp = bsearch(&ip, maps_by_address, nr_maps, sizeof(*mapp),
+					       map__addr_cmp);
 			if (mapp)
 				result = map__get(*mapp);
 			done = true;