# CVE-2024-27009: s390/cio: fix race condition during online processing

> A race condition in the Linux kernel s390/cio subsystem can cause device online processing to fail, leaving devices in an inconsistent state and preventing subsequent operations.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/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:** 1 May 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-27009, DEBIAN-CVE-2024-27009, GHSA-g3g5-xm8m-gp96, UBUNTU-CVE-2024-27009

## What is CVE-2024-27009?

CVE-2024-27009 is a medium-severity vulnerability in Linux kernel, published on 1 May 2024. 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:

s390/cio: fix race condition during online processing

A race condition exists in ccw_device_set_online() that can cause the
online process to fail, leaving the affected device in an inconsistent
state. As a result, subsequent attempts to set that device online fail
with return code ENODEV.

The problem occurs when a path verification request arrives after
a wait for final device state completed, but before the result state
is evaluated.

Fix this by ensuring that the CCW-device lock is held between
determining final state and checking result state.

Note that since:

commit 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers")

path verification requests are much more likely to occur during boot,
resulting in an increased chance of this race condition occurring.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2024-27009?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-27009?

Apply the vendor's patch.

## Is CVE-2024-27009 being exploited?

There is no known exploitation of CVE-2024-27009 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-27009 and fix it if it is affected.

What it is: CVE-2024-27009 is a medium-severity vulnerability in Linux kernel, published on 1 May 2024. 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-2024-27009 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2024-27009/ (Markdown: https://insights.sbomify.com/CVE-2024-27009/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-27009
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-27009
- OSV: https://osv.dev/vulnerability/CVE-2024-27009

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-27009/
Summaries are generated and may contain mistakes; the official description above is the record.