[PATCH] drm/amdgpu: fixx NULL pointer deref in gmc_v9_0_get_vm_pte

[Christian König]

We not only need to make sure that we have a BO, but also that the BO
has some backing store.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index 50386eb2eec8..afc0cfed5065 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -1185,6 +1185,8 @@ static void gmc_v9_0_get_vm_pte(struct amdgpu_device *adev,
 				struct amdgpu_bo_va_mapping *mapping,
 				uint64_t *flags)
 {
+	struct amdgpu_bo *bo = mapping->bo_va->base.bo;
+
 	*flags &= ~AMDGPU_PTE_EXECUTABLE;
 	*flags |= mapping->flags & AMDGPU_PTE_EXECUTABLE;
 
@@ -1196,7 +1198,7 @@ static void gmc_v9_0_get_vm_pte(struct amdgpu_device *adev,
 		*flags &= ~AMDGPU_PTE_VALID;
 	}
 
-	if (mapping->bo_va->base.bo)
+	if (bo && bo->resource)
 		gmc_v9_0_get_coherence_flags(adev, mapping->bo_va->base.bo,
 					     mapping, flags);
 }
-- 
2.34.1