# CVE-2026-68205: media: v4l2-fwnode: Fix subdev owner overwritten in v4l2_async_register_subdev_sensor()

> A race condition in the Linux kernel media subsystem allows premature removal of sensor modules, potentially causing system crashes or denial of service.

- **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:** 10 Aug 2026
- **Updated:** 23 Aug 2026
- **Also known as:** AZL-94749, BELL-CVE-2026-68205, DEBIAN-CVE-2026-68205, GHSA-j4hh-43cp-m365, UBUNTU-CVE-2026-68205

## What is CVE-2026-68205?

CVE-2026-68205 is a vulnerability in Linux, published on 10 Aug 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: v4l2-fwnode: Fix subdev owner overwritten in v4l2_async_register_subdev_sensor()

The v4l2 helper v4l2_async_register_subdev_sensor() calls
v4l2_async_register_subdev(), which is a macro that expands to
__v4l2_async_register_subdev(sd,THIS_MODULE). Since the macro is expanded
inside v4l2-fwnode.c, THIS_MODULE resolves to the v4l2-fwnode module
rather than the sensor driver module that originally set sd->owner. When
v4l2-fwnode is built-in, THIS_MODULE evaluates to NULL, which then
overwrites the sensor driver's owner with NULL.

This causes the problem that the sensor module's reference count is never
incremented during async registration, so the module can be removed while
the subdevice is still in use by a notifier (e.g., a CSI-2 receiver
bridge driver).

Fix this by renaming v4l2_async_register_subdev_sensor() to
__v4l2_async_register_subdev_sensor() with an added explicit module
argument and introducing a wrapper macro:
    #define v4l2_async_register_subdev_sensor(sd) \
        __v4l2_async_register_subdev_sensor(sd, THIS_MODULE)

This ensures the sensor driver module is properly referenced even when
the sensor driver does not init the owner field before calling
v4l2_async_register_subdev_sensor() and prevents premature module removal.

## Which versions are affected by CVE-2026-68205?


## How do I fix CVE-2026-68205?

Apply the vendor's patch.

## Is CVE-2026-68205 being exploited?

There is no known exploitation of CVE-2026-68205 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68205 and fix it if it is affected.

What it is: CVE-2026-68205 is a vulnerability in Linux, published on 10 Aug 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-2026-68205 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-2026-68205/ (Markdown: https://insights.sbomify.com/CVE-2026-68205/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68205
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68205
- OSV: https://osv.dev/vulnerability/CVE-2026-68205

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68205/
Summaries are generated and may contain mistakes; the official description above is the record.