CVE-2021-4154

Name	CVE-2021-4154
Description	A use-after-free flaw was found in cgroup1_parse_param in kernel/cgroup/cgroup-v1.c in the Linux kernel's cgroup v1 parser. A local attacker with a user privilege could cause a privilege escalation by exploiting the fsconfig syscall parameter leading to a container breakout and a denial of service on the system.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, 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)	4.19.269-1	fixed
	bullseye	5.10.158-2	fixed
	bullseye (security)	5.10.162-1	fixed
	bookworm	6.1.15-1	fixed
	sid	6.1.20-1	fixed

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

Package	Type	Release	Fixed Version
linux	source	stretch	(not affected)
linux	source	buster	(not affected)
linux	source	bullseye	5.10.70-1
linux	source	(unstable)	5.14.6-1

Notes

[buster] - linux <not-affected> (Vulnerable code not present)
[stretch] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/3b0462726e7ef281c35a7a4ae33e93ee2bc9975b (5.14-rc2)