From: qianyi liu liuqianyi125@gmail.com

The last_scheduled fence leaks when an entity is being killed and adding the cleanup callback fails.

Decrement the reference count of prev when dma_fence_add_callback() fails, ensuring proper balance.

Cc: stable@vger.kernel.org Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini") Signed-off-by: qianyi liu liuqianyi125@gmail.com --- v3 -> v4: Improve commit message and add code comments (Philipp) v2 -> v3: Rework commit message (Markus) v1 -> v2: Added 'Fixes:' tag and clarified commit message (Philipp and Matthew) --- drivers/gpu/drm/scheduler/sched_entity.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 69bcf0e99d57..da00572d7d42 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -259,9 +259,16 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity) struct drm_sched_fence *s_fence = job->s_fence;

dma_fence_get(&s_fence->finished); - if (!prev || dma_fence_add_callback(prev, &job->finish_cb, - drm_sched_entity_kill_jobs_cb)) + if (!prev || + dma_fence_add_callback(prev, &job->finish_cb, + drm_sched_entity_kill_jobs_cb)) { + /* + * Adding callback above failed. + * dma_fence_put() checks for NULL. + */ + dma_fence_put(prev); drm_sched_entity_kill_jobs_cb(NULL, &job->finish_cb); + }

prev = &s_fence->finished; }