# CVE-2026-89741: Revert "media: v4l2-dev: fix error handling in __video_register_device()"

> A double-free vulnerability in the Linux kernel's V4L2 subsystem allows attackers to potentially execute code or cause a system crash.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-100433, BELL-CVE-2026-89741, DEBIAN-CVE-2026-89741, GHSA-x4c4-qfr2-c3vv, UBUNTU-CVE-2026-89741

## What is CVE-2026-89741?

CVE-2026-89741 is a high-severity use after free vulnerability in Linux, published on 11 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:

Revert "media: v4l2-dev: fix error handling in __video_register_device()"

This reverts commit 2a934fdb01db6458288fc9386d3d8ceba6dd551a.

The intentions of that patch were good, but it doesn't work.

The idea is that if device_register fails, you have to do a put_device
to let the ref counter release resources.

However, the V4L2 API says that if video_register_device() fails, then
you have to call video_device_release(), which kfree()s the video_device
struct.

But the put_device() will already have freed the struct, so you end
up in a double-free scenario.

There is not really a good way of fixing this without breaking
video_register_device() into two parts, one that initializes everything,
and one that does the actual device_register, and then converting all
V4L2 drivers to this new model.

That is a massive job, and it is very unlikely that device_register
will fail.

So rather than ending up in a double-free scenario, just revert this
patch, and in that case we'll have a small memory leak. Which is a lot
more robust.

## Which versions are affected by CVE-2026-89741?


## How do I fix CVE-2026-89741?

Apply the vendor's patch.

## Is CVE-2026-89741 being exploited?

There is no known exploitation of CVE-2026-89741 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89741 and fix it if it is affected.

What it is: CVE-2026-89741 is a high-severity use after free vulnerability in Linux, published on 11 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-2026-89741 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-2026-89741/ (Markdown: https://insights.sbomify.com/CVE-2026-89741/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89741
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89741
- OSV: https://osv.dev/vulnerability/CVE-2026-89741

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89741/
Summaries are generated and may contain mistakes; the official description above is the record.