# CVE-2026-99189: gpio: mxc: fix race between chained IRQ handler install and probe completion


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 28 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** AZL-111353, BELL-CVE-2026-99189, DEBIAN-CVE-2026-99189, GHSA-ghxr-2qfh-mxwc, UBUNTU-CVE-2026-99189

## What is CVE-2026-99189?

CVE-2026-99189 is a vulnerability in Linux, published on 28 Oct 2026. 

### Official description

In the Linux kernel, the following vulnerability has been resolved:

gpio: mxc: fix race between chained IRQ handler install and probe completion

mxc_update_irq_chained_handler() is called before the IRQ domain, the
generic IRQ chip, and the port list entry are set up. If an interrupt
arrives in that window:

 - mx3_gpio_irq_handler() calls generic_handle_domain_irq() with
   port->domain still NULL.
 - mx2_gpio_irq_handler() walks mxc_gpio_ports, but the port has not
   been added to the list yet.

Additionally, if any of the subsequent probe steps
(gpio_generic_chip_init(), devm_gpiochip_add_data(),
irq_domain_create_legacy(), or mxc_gpio_init_gc()) fail, the error
paths never unregister the chained handler, leaving a dangling handler
that points at freed memory.

Move the handler installation after all its dependencies are ready and
after list_add_tail(), so the handler is never live while the data
structures it touches are incomplete, and is never installed if probe
fails.

## Which versions are affected by CVE-2026-99189?


## How do I fix CVE-2026-99189?

Upgrade to a fixed version.

## Is CVE-2026-99189 being exploited?

There is no known exploitation of CVE-2026-99189 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-99189 and fix it if it is affected.

What it is: CVE-2026-99189 is a vulnerability in Linux, published on 28 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-99189 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-2026-99189/ (Markdown: https://insights.sbomify.com/CVE-2026-99189/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-99189
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-99189
- OSV: https://osv.dev/vulnerability/CVE-2026-99189

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-99189/
Summaries are generated and may contain mistakes; the official description above is the record.