In etm_setup_aux(), when a user sink is obtained via
coresight_get_sink_by_id(), it increments the reference count of the
sink device. However, if the sink is used in path building, the path
holds a reference, but the initial reference from
coresight_get_sink_by_id() is not released, causing a reference count
leak. We should release the initial reference after the path is built.
Found by code review.
Cc: stable@vger.kernel.org
Fixes: 0e6c20517596 ("coresight: etm-perf: Allow an event to use different sinks")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
Changes in v2:
- modified the patch as suggestions.
---
drivers/hwtracing/coresight/coresight-etm-perf.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 17afa0f4cdee..56d012ab6d3a 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -454,6 +454,11 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
goto err;
out:
+ if (user_sink) {
+ put_device(&user_sink->dev);
+ user_sink = NULL;
+ }
+
return event_data;
err:
--
2.17.1