[PATCH v3 1/5] drm/amdgpu: fix NULL deref in error path

[Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>]

IF we hit the "error_free_root" error path, amdgpu_vm_pt_free_root
is called which will clear vm->root.bo so calling amdgpu_bo_unreserve
will crash.
Since root_bo is a reference to the BO previously installed as
vm->root.bo, use it.

Fixes: 8473bfdcb5b1 ("drm/amdgpu: fix error handling in amdgpu_vm_init")
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 000c982816a7..ea8688061237 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2716,7 +2716,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 
 error_free_root:
 	amdgpu_vm_pt_free_root(adev, vm);
-	amdgpu_bo_unreserve(vm->root.bo);
+	amdgpu_bo_unreserve(root_bo);
 	amdgpu_bo_unref(&root_bo);
 
 error_free_delayed:
-- 
2.43.0