CVE-2026-89800 drm/nouveau/uvmm: clear the dirty flag when unwinding an OP_UNMAP_SPARSE
A flaw in the Linux kernel nouveau driver allows local attackers to cause permanent denial of service by triggering a specific GPU memory unmap failure.
- 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-2026-89800?
CVE-2026-89800 is a denial of service 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/nouveau/uvmm: clear the dirty flag when unwinding an OP_UNMAP_SPARSE
A successful OP_UNMAP_SPARSE marks its region dirty with nouveau_uvma_region_dirty() and defers the teardown to nouveau_uvmm_bind_job_cleanup(); it does not remove the region from uvmm->region_mt.
If a later op in the job fails, the unwind path never clears reg->dirty (set in one place, cleared nowhere) and sets op->reg = NULL, so cleanup skips the teardown. The region is left in the tree with dirty set and its completion never signalled. Later binds over that range then fail permanently -- -ENOENT or -EINVAL from the dirty checks, or an unkillable wait_for_completion() in bind_validate_region() -- for the lifetime of the uvmm.
Clear reg->dirty when the unwind reverts the sparse unmap, restoring the region to the state it was found in.
Which versions are affected by CVE-2026-89800?
How do I fix CVE-2026-89800?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-89800 being exploited?
There is no known exploitation of CVE-2026-89800 in the wild and no public exploit code.
Sources
Also known as AZL-101622, BELL-CVE-2026-89800, DEBIAN-CVE-2026-89800, GHSA-g7qr-ggg3-47g8, UBUNTU-CVE-2026-89800.