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

[Luben Tuikov]

Right--I just double checked with the koops and it is exactly the "resource" pointer
in the tbo which is NULL.

Reviewed-by:Luben Tuikov <luben.tuikov at amd.com>

Regards,
Luben

On 2022-12-07 02:49, Christian König wrote:
> 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);
>  }