# CVE-2026-89769: clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path

> A use-after-free vulnerability in the NXP PIT clocksource driver allows attackers to potentially execute code or cause a denial of service via an IRQ leak.

- **Severity:** High 7.4 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89769, DEBIAN-CVE-2026-89769, GHSA-8vp9-2h56-3438, UBUNTU-CVE-2026-89769

## What is CVE-2026-89769?

CVE-2026-89769 is a high-severity use after free vulnerability in Linux, published on 11 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:

clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path

When cpuhp_setup_state fails after pit_clockevent_per_cpu_init has
successfully called request_irq, the error handling jumps directly to
out_pit_clocksource_unregister without freeing the registered IRQ.

This leaks the IRQ line and, since kfree(pit) follows, leaves a
dangling pointer registered as the interrupt handler's dev_id,
potentially leading to a use-after-free if the IRQ fires afterwards.

Fix it by calling pit_clockevent_per_cpu_exit to properly release the
IRQ before falling through to the existing cleanup chain.

## Which versions are affected by CVE-2026-89769?


## How do I fix CVE-2026-89769?

Apply the vendor's patch.

## Is CVE-2026-89769 being exploited?

There is no known exploitation of CVE-2026-89769 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89769 and fix it if it is affected.

What it is: CVE-2026-89769 is a high-severity use after free vulnerability in Linux, published on 11 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-2026-89769 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-2026-89769/ (Markdown: https://insights.sbomify.com/CVE-2026-89769/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89769
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89769
- OSV: https://osv.dev/vulnerability/CVE-2026-89769

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89769/
Summaries are generated and may contain mistakes; the official description above is the record.