[PATCH] drm/amdgpu: Fix potential dma_fence leak in amdgpu_ttm_clear_buffer

[Li Ma]

The original code did not properly release the dma_fence `next` in case
amdgpu_ttm_fill_mem failed during buffer clearing.

Signed-off-by: Li Ma <li.ma at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 9c5df35f05b7..b7284f0a5ac0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2296,6 +2296,7 @@ int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
 	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
 	struct amdgpu_ring *ring = adev->mman.buffer_funcs_ring;
 	struct amdgpu_res_cursor cursor;
+	struct dma_fence *next = NULL;
 	u64 addr;
 	int r = 0;
 
@@ -2311,7 +2312,6 @@ int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
 
 	mutex_lock(&adev->mman.gtt_window_lock);
 	while (cursor.remaining) {
-		struct dma_fence *next = NULL;
 		u64 size;
 
 		if (amdgpu_res_cleared(&cursor)) {
@@ -2334,10 +2334,13 @@ int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
 
 		dma_fence_put(*fence);
 		*fence = next;
+		next = NULL;
 
 		amdgpu_res_next(&cursor, size);
 	}
 err:
+	if (next)
+		dma_fence_put(next);
 	mutex_unlock(&adev->mman.gtt_window_lock);
 
 	return r;
-- 
2.25.1