# CVE-2026-89938: iio: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF

> A use-after-free in the Linux kernel Atlas sensor driver allows attackers to execute arbitrary code or escalate privileges via race conditions during device removal.

- **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:** AZL-101132, BELL-CVE-2026-89938, DEBIAN-CVE-2026-89938, GHSA-cv98-fww9-9mfg, UBUNTU-CVE-2026-89938

## What is CVE-2026-89938?

CVE-2026-89938 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: chemical: atlas-sensor: use iio_trigger_poll_nested() to fix remove UAF

The atlas driver requests its hardware data-ready IRQ with
devm_request_threaded_irq(); its threaded handler queues an irq_work,
atlas_work_handler(), that calls iio_trigger_poll(data->trig).

The IRQ is devm-managed, so free_irq() runs from the devres unwind after
atlas_remove() returns without flushing that irq_work.  Once a buffer is
enabled, conversion-complete IRQs keep firing and queueing it; a pending
irq_work can therefore run after the unwind has freed atlas_data/indio_dev
and the trigger, when atlas_work_handler() derives the atlas_data pointer
via container_of() and dereferences data->trig, a use-after-free.

Call iio_trigger_poll_nested() directly from the threaded handler instead
of bouncing through irq_work.  free_irq() then drains the threaded handler,
closing the window; other iio drivers with a threaded data-ready IRQ do the
same (e.g. bmi270).

This issue was found by an in-house static analysis tool.

## Which versions are affected by CVE-2026-89938?


## How do I fix CVE-2026-89938?

Apply the vendor's patch.

## Is CVE-2026-89938 being exploited?

There is no known exploitation of CVE-2026-89938 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89938 and fix it if it is affected.

What it is: CVE-2026-89938 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-2026-89938 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-2026-89938/ (Markdown: https://insights.sbomify.com/CVE-2026-89938/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89938
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89938
- OSV: https://osv.dev/vulnerability/CVE-2026-89938

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89938/
Summaries are generated and may contain mistakes; the official description above is the record.