[PATCH AUTOSEL 6.6 16/18] drm/amdgpu: fix dereference null return value for the function amdgpu_vm_pt_parent

Sasha Levin
2024-06-05T12:04:40Z

From: Jesse Zhang <jesse.zhang@amd.com>

[ Upstream commit a0cf36546cc24ae1c95d72253c7795d4d2fc77aa ]

The pointer parent may be NULLed by the function amdgpu_vm_pt_parent.
To make the code more robust, check the pointer parent.

Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
index 0d51222f6f8eb..026a3db947298 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
@@ -766,11 +766,15 @@ int amdgpu_vm_pde_update(struct amdgpu_vm_update_params *params,
struct amdgpu_vm_bo_base *entry)
{
struct amdgpu_vm_bo_base *parent = amdgpu_vm_pt_parent(entry);
- struct amdgpu_bo *bo = parent->bo, *pbo;
+ struct amdgpu_bo *bo, *pbo;
struct amdgpu_vm *vm = params->vm;
uint64_t pde, pt, flags;
unsigned int level;

+ if (WARN_ON(!parent))
+ return -EINVAL;
+
+ bo = parent->bo;
for (level = 0, pbo = bo->parent; pbo; ++level)
pbo = pbo->parent;

--
2.43.0