CVE-2021-4001

Name	CVE-2021-4001
Description	A race condition was found in the Linux kernel's ebpf verifier between bpf_map_update_elem and bpf_map_freeze due to a missing lock in kernel/bpf/syscall.c. In this flaw, a local user with a special privilege (cap_sys_admin or cap_bpf) can modify the frozen mapped address space. This flaw affects kernel versions prior to 5.16 rc2.
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)	4.19.282-1	fixed
	bullseye	5.10.178-3	fixed
	bullseye (security)	5.10.179-1	fixed
	bookworm, sid	6.1.27-1	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	5.10.84-1
linux	source	(unstable)	5.15.5-1

Notes

[buster] - linux <not-affected> (Vulnerable code introduced later)
[stretch] - linux <not-affected> (Vulnerable code introduced later)
https://git.kernel.org/linus/353050be4c19e102178ccc05988101887c25ae53