kernel/ucount.c in the Linux kernel 5.14 through 5.16.4, when unprivileged user namespaces are enabled, allows a use-after-free and privilege escalation because a ucounts object can outlive its namespace.
https://security.netapp.com/advisory/ntap-20220221-0001/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VVSZKUJAZ2VN6LJ35J2B6YD6BOPQTU3B/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HSR3AI2IQGRKZCHNKF6S25JGDKUEAWWL/
https://github.com/torvalds/linux/commit/f9d87929d451d3e649699d0f1d74f71f77ad38f5
https://www.openwall.com/lists/oss-security/2022/01/29/1
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f9d87929d451d3e649699d0f1d74f71f77ad38f5
Source: Mitre, NVD
Published: 2022-01-29
Updated: 2024-11-21
Base Score: 6.9
Vector: CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C
Severity: Medium
Base Score: 7.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity: High
EPSS: 0.00077