drm/amd/amdgpu: validate the shadow BO.

Fixes a rare NULL pointer dereference in amdgpu_ttm_bind.

The issue was found by Nicolai Haehnle.
The patch was tested by Nicolai Haehnle.

Signed-off-by: Alex Xie <AlexBin.Xie@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 5a27749..29d6d84 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -451,7 +451,7 @@ static int amdgpu_cs_validate(void *param, struct amdgpu_bo *bo)
                return r;
 
        if (bo->shadow)
-               r = amdgpu_cs_bo_validate(p, bo);
+               r = amdgpu_cs_bo_validate(p, bo->shadow);
 
        return r;
 }