CVE-2021-22543

Name	CVE-2021-22543
Description	An issue was discovered in Linux: KVM through Improper handling of VM_IO\|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation.
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-2785-1, DLA-2843-1, ELA-535-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	jessie, jessie (lts)	3.16.84-1	vulnerable
	stretch (security)	4.9.320-2	fixed
	stretch (lts), stretch	4.9.320-3	fixed
	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
linux-4.19 (PTS)	stretch (security)	4.19.232-1~deb9u1	fixed
	stretch (lts), stretch	4.19.304-1~deb9u1	fixed
linux-4.9 (PTS)	jessie, jessie (lts)	4.9.303-1~deb8u3	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin
linux	source	jessie	(unfixed)	end-of-life
linux	source	stretch	4.9.290-1		DLA-2843-1
linux	source	buster	4.19.208-1
linux	source	(unstable)	5.10.46-2
linux-4.19	source	stretch	4.19.208-1~deb9u1		DLA-2785-1
linux-4.9	source	jessie	4.9.290-1~deb8u1		ELA-535-1

Notes

https://www.openwall.com/lists/oss-security/2021/05/26/3
https://github.com/google/security-research/security/advisories/GHSA-7wq5-phmq-m584
https://git.kernel.org/linus/f8be156be163a052a067306417cd0ff679068c97