# CVE-2026-90116: ALSA: mtpav: shut down output timer before card teardown

> A race condition in the ALSA mtpav driver allows a use-after-free during card teardown, potentially causing a kernel crash.

- **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:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-102968, BELL-CVE-2026-90116, DEBIAN-CVE-2026-90116, GHSA-f6xw-5hrw-vj32, UBUNTU-CVE-2026-90116

## What is CVE-2026-90116?

CVE-2026-90116 is a vulnerability in Linux, published on 17 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:

ALSA: mtpav: shut down output timer before card teardown

snd_mtpav_output_timer() rearms chip->timer while holding
chip->spinlock and accesses the card-private mtpav state.

snd_mtpav_free() currently takes the same lock and calls
timer_delete() when the timer is active. This only removes a
pending timer; it does not wait for a callback that is already
running and does not prevent the callback from rearming the timer.

A callback running on another CPU can therefore continue after
snd_mtpav_free() releases the lock and access the card-private
state while the card is being torn down. It can also rearm the
timer after timer_delete() has returned.

Call timer_shutdown_sync() without holding chip->spinlock. This
waits for any running callback to finish and prevents further
rearming before the card-private mtpav state is released.

## Which versions are affected by CVE-2026-90116?


## How do I fix CVE-2026-90116?

Apply the vendor's patch.

## Is CVE-2026-90116 being exploited?

There is no known exploitation of CVE-2026-90116 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90116 and fix it if it is affected.

What it is: CVE-2026-90116 is a vulnerability in Linux, published on 17 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-2026-90116 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-2026-90116/ (Markdown: https://insights.sbomify.com/CVE-2026-90116/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90116
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90116
- OSV: https://osv.dev/vulnerability/CVE-2026-90116

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90116/
Summaries are generated and may contain mistakes; the official description above is the record.