# CVE-2026-98669: iio: buffer: serialize buffer teardown with mode claims

> A race condition in the Linux kernel IIO buffer subsystem allows local attackers to cause a denial of service by invalidating buffer state during device unregistration.

- **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:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-109329, BELL-CVE-2026-98669, DEBIAN-CVE-2026-98669, GHSA-h3hh-6rf8-4cq6, UBUNTU-CVE-2026-98669

## What is CVE-2026-98669?

CVE-2026-98669 is a vulnerability in Linux, published on 18 Oct 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:

iio: buffer: serialize buffer teardown with mode claims

Buffer-mode claims hold mlock to guarantee that the device remains in
buffer mode until the claim is released. Normal buffer updates take
info_exist_lock followed by mlock in iio_update_buffers().

However, iio_device_unregister() disables and deactivates all buffers
without taking mlock. This can invalidate buffer state, including
active_scan_mask, while a buffer-mode claim is held.

Take mlock in iio_disable_all_buffers() so that unregister honors the
mode-claim lifetime guarantee. The info_exist_lock -> mlock ordering
matches iio_update_buffers().

## Which versions are affected by CVE-2026-98669?


## How do I fix CVE-2026-98669?

Apply the vendor's patch.

## Is CVE-2026-98669 being exploited?

There is no known exploitation of CVE-2026-98669 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98669 and fix it if it is affected.

What it is: CVE-2026-98669 is a vulnerability in Linux, published on 18 Oct 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-2026-98669 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-2026-98669/ (Markdown: https://insights.sbomify.com/CVE-2026-98669/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98669
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98669
- OSV: https://osv.dev/vulnerability/CVE-2026-98669

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98669/
Summaries are generated and may contain mistakes; the official description above is the record.