This is a note to let you know that I've just added the patch titled drm/amdgpu: Fix potential fence use-after-free v2 to the 6.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amdgpu-fix-potential-fence-use-after-free-v2.patch and it can be found in the queue-6.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c40edde3756deade9ab970be698727d90fd79f27 Author: shanzhulig <shanzhulig@xxxxxxxxx> Date: Tue Jun 27 18:10:47 2023 -0700 drm/amdgpu: Fix potential fence use-after-free v2 [ Upstream commit 2e54154b9f27262efd0cb4f903cc7d5ad1fe9628 ] fence Decrements the reference count before exiting. Avoid Race Vulnerabilities for fence use-after-free. v2 (chk): actually fix the use after free and not just move it. Signed-off-by: shanzhulig <shanzhulig@xxxxxxxxx> Signed-off-by: Christian König <christian.koenig@xxxxxxx> Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index feb48bb0b4494..0c023269aadaa 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -1625,15 +1625,15 @@ static int amdgpu_cs_wait_all_fences(struct amdgpu_device *adev, continue; r = dma_fence_wait_timeout(fence, true, timeout); + if (r > 0 && fence->error) + r = fence->error; + dma_fence_put(fence); if (r < 0) return r; if (r == 0) break; - - if (fence->error) - return fence->error; } memset(wait, 0, sizeof(*wait));