[PATCH v2] perf pmu: Handle memory failure in tool_pmu__new()

[PATCH v2] 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@linux.ibm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Cc: Ian Rogers <irogers@google.com>
---
 tools/perf/util/pmus.c     | 3 ++-
 tools/perf/util/tool_pmu.c | 8 ++++++++
 2 files changed, 10 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..97b327d1ce4a 100644
--- a/tools/perf/util/tool_pmu.c
+++ b/tools/perf/util/tool_pmu.c
@@ -495,12 +495,20 @@ 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);
+		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

Re: [PATCH v2] perf pmu: Handle memory failure in tool_pmu__new()

[Namhyung Kim]

On Wed, 19 Mar 2025 13:28:20 +0100, Thomas Richter wrote:
> 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.
> 
> [...]
Applied to perf-tools-next, thanks!

Best regards,
Namhyung