CVE-2025-21856

Name	CVE-2025-21856
Description	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.244-1	fixed
	bookworm	6.1.148-1	fixed
	bookworm (security)	6.1.153-1	fixed
	trixie	6.12.43-1	fixed
	trixie (security)	6.12.48-1	fixed
	forky, sid	6.16.12-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
linux	source	bullseye	(not affected)
linux	source	bookworm	(not affected)
linux	source	(unstable)	6.12.17-1

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/915e34d5ad35a6a9e56113f852ade4a730fb88f0 (6.14-rc4)