On 15/12/2025 04:27, Ma Ke wrote:

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.

I think Leo's comment on the previous v2 is still unaddressed. But releasing it in coresight_get_sink_by_id() would make it consistent with coresight_find_csdev_by_fwnode() and prevent further mistakes.

It also leads me to see that users of coresight_find_device_by_fwnode() should also release it, but only one out of two appears to.

James

---

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: