# CVE-2026-89816: drm: Fix drm_crtc_commit leak if signaled when PAGE_FLIP_EVENT is used

> A memory leak in the Linux kernel DRM subsystem allows local attackers to cause denial of service by triggering specific page flip events.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101247, BELL-CVE-2026-89816, DEBIAN-CVE-2026-89816, GHSA-6f96-mhg4-cfw6, UBUNTU-CVE-2026-89816

## What is CVE-2026-89816?

CVE-2026-89816 is a memory corruption 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: Fix drm_crtc_commit leak if signaled when PAGE_FLIP_EVENT is used

Commit 1c6ceeee6ebb ("drm/atomic: Fix memleak on ERESTARTSYS during
non-blocking commits") fixed a very similar issue when the event was
allocated by drm_atomic_helper_setup_commit() itself.

However, if the event is allocated in prepare_signaling(), it will also be
set to NULL in complete_signaling(), which prevents drm_crtc_commit from
being put in __drm_atomic_helper_crtc_destroy_state().

Dropping the reference when the event is set to NULL at
complete_signaling() fixes the leak.

The leak can be reproduced by sending a signal to the thread using
DRM_MODE_PAGE_FLIP_EVENT and using a sw_sync fence to cause the atomic
ioctl to block at drm_atomic_helper_wait_for_fences(). It happened both
with amdgpu and vkms.

## Which versions are affected by CVE-2026-89816?


## How do I fix CVE-2026-89816?

Apply the vendor's patch.

## Is CVE-2026-89816 being exploited?

There is no known exploitation of CVE-2026-89816 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89816 and fix it if it is affected.

What it is: CVE-2026-89816 is a memory corruption 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.
Exploitation: There is no known exploitation of CVE-2026-89816 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-2026-89816/ (Markdown: https://insights.sbomify.com/CVE-2026-89816/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89816
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89816
- OSV: https://osv.dev/vulnerability/CVE-2026-89816

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89816/
Summaries are generated and may contain mistakes; the official description above is the record.