[PATCH] perf pmu: Handle memory failure in tool_pmu__new()

[Thomas Richter]

On linux-next
commit 72c6f57a4193 ("perf pmu: Dynamically allocate tool PMU")
allocated PMU named "tool" dynamicly. However that allocation
can fail and a NULL pointer is returned. That case is currently
not handled and would result in an invalid address reference.
Add a check for NULL pointer.

Fixes: 72c6f57a4193 ("perf pmu: Dynamically allocate tool PMU")
Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxxxxx>
---
 tools/perf/util/pmus.c     | 3 ++-
 tools/perf/util/tool_pmu.c | 9 +++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 9b5a63ecb249..b99292de7669 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -265,7 +265,8 @@ static void pmu_read_sysfs(unsigned int to_read_types)
 	if ((to_read_types & PERF_TOOL_PMU_TYPE_TOOL_MASK) != 0 &&
 	    (read_pmu_types & PERF_TOOL_PMU_TYPE_TOOL_MASK) == 0) {
 		tool_pmu = tool_pmu__new();
-		list_add_tail(&tool_pmu->list, &other_pmus);
+		if (tool_pmu)
+			list_add_tail(&tool_pmu->list, &other_pmus);
 	}
 	if ((to_read_types & PERF_TOOL_PMU_TYPE_HWMON_MASK) != 0 &&
 	    (read_pmu_types & PERF_TOOL_PMU_TYPE_HWMON_MASK) == 0)
diff --git a/tools/perf/util/tool_pmu.c b/tools/perf/util/tool_pmu.c
index b60ac390d52d..d764c4734be6 100644
--- a/tools/perf/util/tool_pmu.c
+++ b/tools/perf/util/tool_pmu.c
@@ -495,12 +495,21 @@ struct perf_pmu *tool_pmu__new(void)
 {
 	struct perf_pmu *tool = zalloc(sizeof(struct perf_pmu));
 
+	if (!tool)
+		goto out;
 	tool->name = strdup("tool");
+	if (!tool->name) {
+		zfree(tool);
+		tool = NULL;
+		goto out;
+	}
+
 	tool->type = PERF_PMU_TYPE_TOOL;
 	INIT_LIST_HEAD(&tool->aliases);
 	INIT_LIST_HEAD(&tool->caps);
 	INIT_LIST_HEAD(&tool->format);
 	tool->events_table = find_core_events_table("common", "common");
 
+out:
 	return tool;
 }
-- 
2.48.1