CVE-2026-98512 drm/nouveau: RCU-free the scheduler-containing nouveau_sched
An unprivileged local user can trigger a use-after-free in the nouveau GPU driver via sync file operations, potentially causing a system crash or information leak.
- 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-2026-98512?
CVE-2026-98512 is a high-severity use after free vulnerability in Linux, published on 18 Oct 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/nouveau: RCU-free the scheduler-containing nouveau_sched
struct nouveau_sched embeds a struct drm_gpu_scheduler (base). nouveau_sched_destroy() calls nouveau_sched_fini() (which does drm_sched_fini(&sched->base)) and then frees the object with plain kfree(sched).
drm_sched_fence_get_timeline_name() returns fence->sched->name, and the scheduler fence keeps a .release callback so it is not ops-detached on signalling. A finished fence exported to userspace via drm_syncobj / sync_file therefore keeps pointing at &sched->base after nouveau_sched_destroy(), and a later get_timeline_name() -- reachable unprivileged through SYNC_IOC_FILE_INFO -- dereferences freed memory (KASAN slab-use-after-free read).
Per the dma-fence lifetime contract the exporter must keep the data backing a signalled fence alive for an RCU grace period. Free the scheduler-containing object with kfree_rcu() instead of kfree().
Which versions are affected by CVE-2026-98512?
How do I fix CVE-2026-98512?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-98512 being exploited?
There is no known exploitation of CVE-2026-98512 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98512, DEBIAN-CVE-2026-98512, GHSA-2689-7jhq-fvhw, UBUNTU-CVE-2026-98512.