CVE-2026-89828 drm/amdgpu: Fix init ordering in amdgpu_vram_mgr_init()
A null pointer dereference in the amdgpu driver during module load failure causes a kernel panic, leading to local denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89828?
CVE-2026-89828 is a vulnerability in Linux, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix init ordering in amdgpu_vram_mgr_init()
drmm_cgroup_register_region() is called before INIT_LIST_HEAD() and gpu_buddy_init() in amdgpu_vram_mgr_init(). If it fails, the function returns early and bypasses those initializations.
Since adev->mman.initialized is set to true before amdgpu_vram_mgr_init() is called, a failure triggers amdgpu_ttm_fini(), which calls amdgpu_vram_mgr_fini(), which then:
- Calls list_for_each_entry_safe() on reservations_pending and reserved_pages, whose list_head::next pointers are zero-initialized (NULL). The loop does not recognize them as empty and dereferences NULL.
- Calls gpu_buddy_fini(), which iterates free_trees[] unconditionally via for_each_free_tree(). Since mm->free_trees is NULL (never allocated), this dereferences NULL.
Both result in a kernel panic on the module load error path.
Fix by moving drmm_cgroup_register_region() to after the list and buddy allocator are fully initialized, so the teardown path is safe to run.
Which versions are affected by CVE-2026-89828?
How do I fix CVE-2026-89828?
Apply the vendor's patch.
Is CVE-2026-89828 being exploited?
There is no known exploitation of CVE-2026-89828 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89828, DEBIAN-CVE-2026-89828, GHSA-ccvg-gmvq-q8w3, UBUNTU-CVE-2026-89828.