# CVE-2026-80919: drm/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format

> A recursive locking bug in the amdgpu driver can cause a kernel deadlock and log flooding when dumping hung jobs, leading to denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Sep 2026
- **Updated:** 9 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-80919, GHSA-97pv-pqpm-w4fg, UBUNTU-CVE-2026-80919

## What is CVE-2026-80919?

CVE-2026-80919 is a denial of service vulnerability in Linux, published on 9 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/amdgpu: fix recursive ww_mutex acquire in amdgpu_devcoredump_format

When dumping IB contents from a hung job, amdgpu_devcoredump_format()
acquired the VM root PD's reservation via amdgpu_vm_lock_by_pasid() and
then, for each IB, called amdgpu_bo_reserve() on the BO backing the IB.
Both reservations are reservation_ww_class_mutex objects and neither
used a ww_acquire_ctx, which trips lockdep:

  WARNING: possible recursive locking detected
  --------------------------------------------
  kworker/u128:0 is trying to acquire lock:
  ffff88838b16e1f0 (reservation_ww_class_mutex){+.+.}-{4:4},
    at: amdgpu_devcoredump_format+0x1594/0x23f0 [amdgpu]

  but task is already holding lock:
  ffff8882f82681f0 (reservation_ww_class_mutex){+.+.}-{4:4},
    at: amdgpu_devcoredump_format+0x1594/0x23f0 [amdgpu]

   Possible unsafe locking scenario:
         CPU0
         ----
    lock(reservation_ww_class_mutex);
    lock(reservation_ww_class_mutex);

   *** DEADLOCK ***
   May be due to missing lock nesting notation

  Workqueue: events_unbound amdgpu_devcoredump_deferred_work [amdgpu]
  Call Trace:
   __ww_mutex_lock.constprop.0
   ww_mutex_lock
   amdgpu_bo_reserve
   amdgpu_devcoredump_format+0x1594 [amdgpu]
   amdgpu_devcoredump_deferred_work+0xea [amdgpu]

The two reservations are on different BOs in the captured trace, so the
splat is a lockdep-correctness warning, not an observed deadlock. It
becomes a real self-deadlock whenever the IB BO shares its dma_resv with
the root PD (the always-valid case, see amdgpu_vm_is_bo_always_valid()):
amdgpu_bo_reserve(abo) re-acquires the same ww_mutex without a ticket
and blocks forever. With amdgpu.gpu_recovery=0 the timeout handler
refires every ~2 s and each invocation produces this splat, drowning the
kernel ring buffer.

Now that amdgpu_vm_lock_by_pasid() takes a drm_exec context, move the IB
dumping into a separate helper that locks the root PD and every IB BO
together in a single drm_exec ticket. DRM_EXEC_IGNORE_DUPLICATES handles
IB BOs that share a dma_resv (e.g. always-valid BOs, or two IBs backed
by the same BO). Every lock is now a top-level acquire under one
ww_acquire_ctx, so the recursive ww_mutex condition is gone, and the
per-IB amdgpu_bo_reserve()/amdgpu_bo_unref() dance -- including a BO
refcount leak on the amdgpu_bo_reserve() failure path -- is removed.

(cherry picked from commit d6bf4242731219ee08ce54c365631e395486651e)

## Which versions are affected by CVE-2026-80919?


## How do I fix CVE-2026-80919?

Apply the vendor's patch.

## Is CVE-2026-80919 being exploited?

There is no known exploitation of CVE-2026-80919 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80919 and fix it if it is affected.

What it is: CVE-2026-80919 is a denial of service vulnerability in Linux, published on 9 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-80919 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-80919/ (Markdown: https://insights.sbomify.com/CVE-2026-80919/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80919
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80919
- OSV: https://osv.dev/vulnerability/CVE-2026-80919

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80919/
Summaries are generated and may contain mistakes; the official description above is the record.