Merge tag 'amd-drm-fixes-6.6-2023-10-19' of https://gitlab.freedeskto…

…p.org/agd5f/linux into drm-fixes

amd-drm-fixes-6.6-2023-10-19:

amdgpu:
- Fix possible NULL pointer dereference
- Avoid possible BUG_ON in GPUVM updates

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231020012417.4876-1-alexander.deucher@amd.com

drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c

@@ -403,7 +403,10 @@ amdgpu_dma_buf_move_notify(struct dma_buf_attachment *attach)
 				continue;
 		}
 
-		r = amdgpu_vm_clear_freed(adev, vm, NULL);
+		/* Reserve fences for two SDMA page table updates */
+		r = dma_resv_reserve_fences(resv, 2);
+		if (!r)
+			r = amdgpu_vm_clear_freed(adev, vm, NULL);
 		if (!r)
 			r = amdgpu_vm_handle_moved(adev, vm);
 

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -1090,7 +1090,8 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev, struct amdgpu_bo_va *bo_va,
 			struct drm_gem_object *gobj = dma_buf->priv;
 			struct amdgpu_bo *abo = gem_to_amdgpu_bo(gobj);
 
-			if (abo->tbo.resource->mem_type == TTM_PL_VRAM)
+			if (abo->tbo.resource &&
+			    abo->tbo.resource->mem_type == TTM_PL_VRAM)
 				bo = gem_to_amdgpu_bo(gobj);
 		}
 		mem = bo->tbo.resource;