CVE-2025-21856: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: s390/ism: add release function for struct device According to device_release() in /drivers/base/core.c, a device without a release function is a broken device and must be fixed. The current code directly frees the device after calling device_add() without waiting for other kernel parts to release their references. Thus, a reference could still be held to a struct device, e.g., by sysfs, leading to potential use-after-free issues if a proper release function is not set.

Affected products

• Linux Linux Kernel: from 6.3, before 6.6.80 (fixed in 6.6.80); from 6.7, before 6.12.17 (fixed in 6.12.17); from 6.13, before 6.13.5 (fixed in 6.13.5); version 6.14 only

Published 2025-03-12. Last modified 2026-06-17.