# CVE-2025-40316: drm/mediatek: Fix device use-after-free on unbind

> A use-after-free vulnerability in the Linux kernel's MediaTek DRM driver allows local attackers to potentially execute code or escalate privileges.

- **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:** 8 Dec 2025
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2025-40316, DEBIAN-CVE-2025-40316, GHSA-wh68-8742-rwwq, ROOT-OS-DEBIAN-13-CVE-2025-40316, UBUNTU-CVE-2025-40316

## What is CVE-2025-40316?

CVE-2025-40316 is an use after free vulnerability in Linux, published on 8 Dec 2025. 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/mediatek: Fix device use-after-free on unbind

A recent change fixed device reference leaks when looking up drm
platform device driver data during bind() but failed to remove a partial
fix which had been added by commit 80805b62ea5b ("drm/mediatek: Fix
kobject put for component sub-drivers").

This results in a reference imbalance on component bind() failures and
on unbind() which could lead to a user-after-free.

Make sure to only drop the references after retrieving the driver data
by effectively reverting the previous partial fix.

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

## Which versions are affected by CVE-2025-40316?


## How do I fix CVE-2025-40316?

Apply the vendor's patch.

## Is CVE-2025-40316 being exploited?

There is no known exploitation of CVE-2025-40316 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40316 and fix it if it is affected.

What it is: CVE-2025-40316 is an use after free vulnerability in Linux, published on 8 Dec 2025. 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-2025-40316 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-2025-40316/ (Markdown: https://insights.sbomify.com/CVE-2025-40316/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40316
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40316
- OSV: https://osv.dev/vulnerability/CVE-2025-40316

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40316/
Summaries are generated and may contain mistakes; the official description above is the record.