# CVE-2026-80548: linux: In the Linux kernel, the following vulnerability has been resolved:  s390/vfio_ccw: Selectively expand io_mutex  The...

CVE-2026-80548 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-80548, released August 27, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-80548
- Priority: High
- CVSS: 8.8 (high)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 26, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  s390/vfio_ccw: Selectively expand io_mutex  The io_mutex was defined to serialize the io_regions, but then has also sort of been associated with the I/O themselves because of the close relationship they share.  With the handful of races that are possible, the choices are either to:  A) expand the scope of io_mutex to close these remaining windows, or  B) reduce the scope of io_mutex to just io_region, and introduce a new     lock mechanism for the remaining I/O resources  This patch implements A, since B brings with it a lot more interactions that would need to be tracked and kept in a correct hierarchy. It also takes advantage of the workqueue element for cp_free() that now gets called out of fsm_notoper(), which could be invoked out of an interrupt context and thus cannot acquire a mutex itself.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.187-1 | [DEBIAN-CVE-2026-80548](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80548.md) | Aug 27, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.105-1 | [DEBIAN-CVE-2026-80548](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80548.md) | Aug 27, 2026 |
| Linux | linux Debian 14 | 7.1.10-1 | [DEBIAN-CVE-2026-80548](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80548.md) | Aug 27, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.107-1~deb12u1 | [DEBIAN-CVE-2026-80548](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80548.md) | Aug 27, 2026 |

---

Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.