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

[Felix Kuehling]

Am 2022-12-07 um 02:49 schrieb 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.koe...@amd.com>

Mea culpa.

Fixes: d1a372af1c3d ("drm/amdgpu: Set MTYPE in PTE based on BO flags")

(using the commit hash from drm-next, not amd-staging-drm-next) Other 
than that, the patch is

Reviewed-by: Felix Kuehling <felix.kuehl...@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);
  }