CVE-2021-46968: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 5.10, before 5.10.36 (fixed in 5.10.36); from 5.11, before 5.11.20 (fixed in 5.11.20); from 5.12, before 5.12.3 (fixed in 5.12.3)

Published 2024-02-27. Last modified 2026-06-17.