Bug 2435641 (CVE-2026-23034)
| Summary: | CVE-2026-23034 kernel: drm/amdgpu/userq: Fix fence reference leak on queue teardown v2 | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | unspecified | CC: | rhel-process-autobot, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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)