CVE-2022-24122
kernel: use-after-free and privilege escalation in kernel/ucount.c when unprivileged user namespaces are enabled
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · January 30, 2022
Updated · November 22, 2025
Description
A use-after-free vulnerability was found in the Linux kernel’s alloc_ucounts in the kernel/ucount.c function. This flaw allows a local attacker with unprivileged user namespaces to cause a privilege escalation problem.
Statement
There was no shipped kernel version that was seen affected by this problem. These files are not built in our source code.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
To mitigate this problem, disable unprivileged user namespaces:
# sysctl -w kernel.unprivileged_userns_clone=0
CVSS / CWE
CVSS 3.1 · 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 · Use After Free