CVE-2021-46968

s390/zcrypt: fix zcard and zqueue hot-unplug memleak

MEDIUM
5.5
CVSS Score
Published: February 27, 2024 at 06:47 PM UTC
Updated: June 17, 2026 at 04:16 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.10 ≤ v < 5.10.365.10 ≤ v < 5.11.205.10 ≤ v < 5.12.35.10 ≤ v < 5.135.11 ≤ v < 5.11.205.12 ≤ v < 5.12.329c2680fd2bf3862ff5cf2957f198512493156f95.10
Vendor states this is fixed in 026499a9c2e002e621ad568d1378324ae97e5524 (fixed)
Vendor states this is fixed in 055a063a18bcd19b93709e3eac8078d6b2f04599 (fixed)
Vendor states this is fixed in 70fac8088cfad9f3b379c9082832b4d7532c16c2 (fixed)
Vendor states this is fixed in 971dc8706cee47393d393905d294ea47e39503d3 (fixed)
Vendor states this is fixed in 5.10 (unaffected)
Vendor states this is fixed in 5.10.36 (unaffected)
Vendor states this is fixed in 5.11.20 (unaffected)
Vendor states this is fixed in 5.12.3 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)

References (4)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/026499a9c2e002e621ad568d1378324ae97e5524
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/055a063a18bcd19b93709e3eac8078d6b2f04599
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/70fac8088cfad9f3b379c9082832b4d7532c16c2
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/971dc8706cee47393d393905d294ea47e39503d3

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-401

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