From: jsg <jsg@openbsd.org>
Date: Fri, 30 Aug 2024 04:03:30 +0000 (+0000)
Subject: drm/amdgpu: fix dereference null return value for the function amdgpu_vm_pt_parent
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=523bdaadbe21dfc94e3f4519ce7a2964ebb2e10f;p=openbsd

drm/amdgpu: fix dereference null return value for the function amdgpu_vm_pt_parent

From Jesse Zhang
3cc03d1dbdcf88d3c05578c286a2e8a07befac93 in linux-6.6.y/6.6.48
511a623fb46a6cf578c61d4f2755783c48807c77 in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/amdgpu/amdgpu_vm_pt.c b/sys/dev/pci/drm/amd/amdgpu/amdgpu_vm_pt.c
index 8da974096bc..8c5e7d09485 100644
--- a/sys/dev/pci/drm/amd/amdgpu/amdgpu_vm_pt.c
+++ b/sys/dev/pci/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;