From e54d9ee1b1ac31fcb420c1943abc3e481ce8b6aa Mon Sep 17 00:00:00 2001 From: Pan Bian Date: Wed, 6 Nov 2019 17:14:45 +0800 Subject: drm/amdgpu: fix potential double drop fence reference MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 946ab8db6953535a3a88c957db8328beacdfed9d ] The object fence is not set to NULL after its reference is dropped. As a result, its reference may be dropped again if error occurs after that, which may lead to a use after free bug. To avoid the issue, fence is explicitly set to NULL after dropping its reference. Acked-by: Christian König Signed-off-by: Pan Bian Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/amdgpu_test.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c index ed8c3739015b..b35b0741fd97 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c @@ -125,6 +125,7 @@ static void amdgpu_do_test_moves(struct amdgpu_device *adev) } dma_fence_put(fence); + fence = NULL; r = amdgpu_bo_kmap(vram_obj, &vram_map); if (r) { @@ -170,6 +171,7 @@ static void amdgpu_do_test_moves(struct amdgpu_device *adev) } dma_fence_put(fence); + fence = NULL; r = amdgpu_bo_kmap(gtt_obj[i], >t_map); if (r) { -- cgit v1.2.3