CVE-2026-23034

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)

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.