From a952f1ab696873be124e31ce5ef964d36bce817f Mon Sep 17 00:00:00 2001
From: qianyi liu <liuqianyi125@gmail.com>
Date: Tue, 11 Mar 2025 14:02:51 +0800
Subject: [PATCH] drm/sched: Fix fence reference count leak
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 # v6.2+
[phasta: add git tag info for stable kernel]
Fixes: 2fdb8a8f07c2 ("drm/scheduler: rework entity flush, kill and fini")
Signed-off-by: qianyi liu <liuqianyi125@gmail.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250311060251.4041101-1-liuqianyi125@gmail.com
---
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 69bcf0e99d57e..da00572d7d42e 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;
}
--
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