# CVE-2026-89871: media: video-i2c: fix kthread error pointer left in kthread_vid_cap on failure

> A local attacker can trigger a kernel crash in the video-i2c driver by exploiting an unhandled error pointer, causing a denial of service.

- **Severity:** Not scored
- **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:** AZL-101376, BELL-CVE-2026-89871, DEBIAN-CVE-2026-89871, GHSA-5fv9-jv39-xhgw, UBUNTU-CVE-2026-89871

## What is CVE-2026-89871?

CVE-2026-89871 is a 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: video-i2c: fix kthread error pointer left in kthread_vid_cap on failure

kthread_run() returns an ERR_PTR on failure, not NULL.
When start_streaming() fails, data->kthread_vid_cap is left holding
this error pointer instead of being cleared.

This causes two subsequent bugs:
1. A future call to start_streaming() sees a non-NULL kthread_vid_cap
   and returns 0 (success) immediately, without actually starting the
   capture thread.
2. A call to stop_streaming() checks 'kthread_vid_cap == NULL' which
   is false for an error pointer, and proceeds to call kthread_stop()
   on the error pointer, leading to a kernel crash.

Fix this by resetting kthread_vid_cap to NULL on failure before
jumping to the error path.

## Which versions are affected by CVE-2026-89871?


## How do I fix CVE-2026-89871?

Apply the vendor's patch.

## Is CVE-2026-89871 being exploited?

There is no known exploitation of CVE-2026-89871 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89871 and fix it if it is affected.

What it is: CVE-2026-89871 is a 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-2026-89871 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-2026-89871/ (Markdown: https://insights.sbomify.com/CVE-2026-89871/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89871
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89871
- OSV: https://osv.dev/vulnerability/CVE-2026-89871

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89871/
Summaries are generated and may contain mistakes; the official description above is the record.