CVE-2021-46968

Name	CVE-2021-46968
Description	In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: fix zcard and zqueue hot-unplug memleak Tests with kvm and a kmemdebug kernel showed, that on hot unplug the zcard and zqueue structs for the unplugged card or queue are not properly freed because of a mismatch with get/put for the embedded kref counter. This fix now adjusts the handling of the kref counters. With init the kref counter starts with 1. This initial value needs to drop to zero with the unregister of the card or queue to trigger the release and free the object.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, 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)	buster	4.19.249-2	fixed
	buster (security)	4.19.304-1	fixed
	bullseye	5.10.209-2	fixed
	bullseye (security)	5.10.216-1	fixed
	bookworm	6.1.76-1	fixed
	bookworm (security)	6.1.90-1	fixed
	sid, trixie	6.7.12-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	buster	(not affected)
linux	source	(unstable)	5.10.38-1

[buster] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/70fac8088cfad9f3b379c9082832b4d7532c16c2 (5.13-rc1)