# CVE-2026-89941: iio: buffer: Make IIO DMA fence release RCU-safe

> A use-after-free vulnerability in the Linux kernel's IIO DMA fence release mechanism allows attackers to potentially execute code or escalate privileges.

- **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:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89941, DEBIAN-CVE-2026-89941, GHSA-m3pj-6mpg-h767, UBUNTU-CVE-2026-89941

## What is CVE-2026-89941?

CVE-2026-89941 is a high-severity use after free 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:

iio: buffer: Make IIO DMA fence release RCU-safe

The `dma_fence` documentation states that if a custom release
implementation is provided, the `dma_fence` object must be freed in an
RCU-safe way. The current `iio_dma_fence` implementation uses `kfree()`,
which might result in a use-after-free.

Remove the custom `release` implementation. This makes the DMA fence core
fall back to `dma_fence_free()`, which calls `kfree_rcu()` on the fence.
This requires that the fence be the first member of `struct iio_dma_fence`.

Using the default release method for extended DMA fence structures is a
common pattern.

## Which versions are affected by CVE-2026-89941?


## How do I fix CVE-2026-89941?

Apply the vendor's patch.

## Is CVE-2026-89941 being exploited?

There is no known exploitation of CVE-2026-89941 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89941 and fix it if it is affected.

What it is: CVE-2026-89941 is a high-severity use after free 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-2026-89941 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-2026-89941/ (Markdown: https://insights.sbomify.com/CVE-2026-89941/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89941
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89941
- OSV: https://osv.dev/vulnerability/CVE-2026-89941

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89941/
Summaries are generated and may contain mistakes; the official description above is the record.