Commit 2a3d252d authored Mar 25, 2020 by Ian Rogers Committed by Arnaldo Carvalho de Melo Mar 26, 2020

perf parse-events: Add defensive NULL check



Terms may have a NULL config in which case a strcmp will SEGV. This can
be reproduced with:

  perf stat -e '*/event=?,nr/' sleep 1

Add a NULL check to avoid this. This was caught by LLVM's libfuzzer.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: clang-built-linux@googlegroups.com
Link: http://lore.kernel.org/lkml/20200325164022.41385-1-irogers@google.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent eadcaa3d

tools/perf/util/pmu.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -984,14 +984,13 @@ static int pmu_resolve_param_term(struct parse_events_term *term,
		struct parse_events_term *t;

		list_for_each_entry(t, head_terms, list) {
		if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
		if (!strcmp(t->config, term->config)) {
		if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM &&
		t->config && !strcmp(t->config, term->config)) {
		t->used = true;
		*value = t->val.num;
		return 0;
		}
		}
		}

		if (verbose > 0)
		printf("Required parameter '%s' not specified\n", term->config);

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