| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.2 124/215] perf session: Fix potential NULL pointer dereference found by the smatch tool | Date | Mon, 29 Jul 2019 21:22:00 +0200 |
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[ Upstream commit f3c8d90757724982e5f07cd77d315eb64ca145ac ]
Based on the following report from Smatch, fix the potential NULL pointer dereference check.
tools/perf/util/session.c:1252 dump_read() error: we previously assumed 'evsel' could be null (see line 1249)
tools/perf/util/session.c 1240 static void dump_read(struct perf_evsel *evsel, union perf_event *event) 1241 { 1242 struct read_event *read_event = &event->read; 1243 u64 read_format; 1244 1245 if (!dump_trace) 1246 return; 1247 1248 printf(": %d %d %s %" PRIu64 "\n", event->read.pid, event->read.tid, 1249 evsel ? perf_evsel__name(evsel) : "FAIL", 1250 event->read.value); 1251 1252 read_format = evsel->attr.read_format; ^^^^^^^
'evsel' could be NULL pointer, for this case this patch directly bails out without dumping read_event.
Signed-off-by: Leo Yan <leo.yan@linaro.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Alexios Zavras <alexios.zavras@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Changbin Du <changbin.du@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com> Cc: Jin Yao <yao.jin@linux.intel.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Song Liu <songliubraving@fb.com> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20190702103420.27540-9-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/session.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 54cf163347f7..2e61dd6a3574 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1249,6 +1249,9 @@ static void dump_read(struct perf_evsel *evsel, union perf_event *event) evsel ? perf_evsel__name(evsel) : "FAIL", event->read.value); + if (!evsel) + return; + read_format = evsel->attr.read_format; if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) -- 2.20.1
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