# CVE-2026-89885: media: platform: mtk-mdp3: Fix SCP device refcounting

> A reference counting error in the MediaTek MDP3 driver can lead to a use-after-free, potentially causing system crashes or arbitrary code execution.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89885, DEBIAN-CVE-2026-89885, GHSA-86m7-6x4j-3vh5, UBUNTU-CVE-2026-89885

## What is CVE-2026-89885?

CVE-2026-89885 is a high-severity use after free 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:

media: platform: mtk-mdp3: Fix SCP device refcounting

mdp_probe() first tries to get the SCP handle with scp_get(). When that
fails, it falls back to looking up the SCP platform device with
__get_pdev_by_id() and then reads its driver data.

The fallback lookup returns the platform device with a reference, just
like scp_get() does. However, the fallback path currently drops that
reference immediately after platform_get_drvdata(). The driver later
still calls scp_put(mdp->scp) unconditionally from the probe error path
and from mdp_video_device_release(), which drops the SCP device
reference again.

Keep the fallback reference until the existing scp_put() call, so that
the fallback path follows the same ownership rules as the scp_get()
path.

## Which versions are affected by CVE-2026-89885?


## How do I fix CVE-2026-89885?

Apply the vendor's patch.

## Is CVE-2026-89885 being exploited?

There is no known exploitation of CVE-2026-89885 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89885 and fix it if it is affected.

What it is: CVE-2026-89885 is a high-severity use after free 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-2026-89885 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-2026-89885/ (Markdown: https://insights.sbomify.com/CVE-2026-89885/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89885
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89885
- OSV: https://osv.dev/vulnerability/CVE-2026-89885

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89885/
Summaries are generated and may contain mistakes; the official description above is the record.