CVE-2026-23034 drm/amdgpu/userq: Fix fence reference leak on queue teardown v2
A missing reference count decrement in the AMD GPU driver causes a memory leak and kernel panic during module unload, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23034?
CVE-2026-23034 is a memory corruption vulnerability in Linux, published on 31 Jan 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/userq: Fix fence reference leak on queue teardown v2
The user mode queue keeps a pointer to the most recent fence in userq->last_fence. This pointer holds an extra dma_fence reference.
When the queue is destroyed, we free the fence driver and its xarray, but we forgot to drop the last_fence reference.
Because of the missing dma_fence_put(), the last fence object can stay alive when the driver unloads. This leaves an allocated object in the amdgpu_userq_fence slab cache and triggers
This is visible during driver unload as:
BUG amdgpu_userq_fence: Objects remaining on __kmem_cache_shutdown() kmem_cache_destroy amdgpu_userq_fence: Slab cache still has objects Call Trace: kmem_cache_destroy amdgpu_userq_fence_slab_fini amdgpu_exit __do_sys_delete_module
Fix this by putting userq->last_fence and clearing the pointer during amdgpu_userq_fence_driver_free().
This makes sure the fence reference is released and the slab cache is empty when the module exits.
v2: Update to only release userq->last_fence with dma_fence_put() (Christian)
(cherry picked from commit 8e051e38a8d45caf6a866d4ff842105b577953bb)
Which versions are affected by CVE-2026-23034?
How do I fix CVE-2026-23034?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-23034 being exploited?
There is no known exploitation of CVE-2026-23034 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-23034, DEBIAN-CVE-2026-23034, GHSA-hv59-hh7h-7h9r, UBUNTU-CVE-2026-23034.