CVE-2026-80548: Linux

High severity, CVSS 8.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux: from 5.2, before 5.15.218 (fixed in 5.15.218); from 5.16, before 6.1.185 (fixed in 6.1.185); from 6.2, before 6.6.153 (fixed in 6.6.153); from 6.7, before 6.12.105 (fixed in 6.12.105); from 6.13, before 6.18.46 (fixed in 6.18.46); from 6.19, before 7.1.10 (fixed in 7.1.10)

Published 2026-08-26. Last modified 2026-08-27.