[PATCH AUTOSEL 6.9 20/23] drm/amdgpu: fix dereference null return value for the function amdgpu_vm_pt_parent
From: Sasha Levin
Date: Wed Jun 05 2024 - 08:33:39 EST
From: Jesse Zhang <jesse.zhang@xxxxxxx>
[ 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@xxxxxxx>
Suggested-by: Christian König <christian.koenig@xxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 124389a6bf481..512b42225003f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
@@ -682,11 +682,15 @@ 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