Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 100/161] drm/amdgpu: fix potential double drop fence reference | Date | Sun, 29 Dec 2019 18:19:08 +0100 |
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From: Pan Bian <bianpan2016@163.com>
[ 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 <christian.koenig@amd.com> Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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) { -- 2.20.1
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