CVE-2021-4083

Name	CVE-2021-4083
Description	A read-after-free memory flaw was found in the Linux kernel's garbage collection for Unix domain socket file handlers in the way users call close() and fget() simultaneously and can potentially trigger a race condition. This flaw allows a local user to crash the system or escalate their privileges on the system. This flaw affects Linux kernel versions prior to 5.16-rc4.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-2940-1, DLA-2941-1, DSA-5096-1

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)	4.19.304-1	fixed
	bullseye	5.10.209-2	fixed
	bullseye (security)	5.10.205-2	fixed
	bookworm	6.1.76-1	fixed
	bookworm (security)	6.1.85-1	fixed
	trixie	6.6.15-2	fixed
	sid	6.7.9-2	fixed

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

Package	Type	Release	Fixed Version	Origin
linux	source	stretch	4.9.303-1	DLA-2940-1
linux	source	buster	4.19.232-1	DSA-5096-1
linux	source	bullseye	5.10.84-1
linux	source	(unstable)	5.15.5-2
linux-4.19	source	stretch	4.19.232-1~deb9u1	DLA-2941-1

https://git.kernel.org/linus/054aa8d439b9185d4f5eb9a90282d1ce74772969 (5.16-rc4)
https://bugs.chromium.org/p/project-zero/issues/detail?id=2247