CVE-2022-23033

Name	CVE-2022-23033
Description	arm: guest_physmap_remove_page not removing the p2m mappings The functions to remove one or more entries from a guest p2m pagetable on Arm (p2m_remove_mapping, guest_physmap_remove_page, and p2m_set_entry with mfn set to INVALID_MFN) do not actually clear the pagetable entry if the entry doesn't have the valid bit set. It is possible to have a valid pagetable entry without the valid bit set when a guest operating system uses set/way cache maintenance instructions. For instance, a guest issuing a set/way cache maintenance instruction, then calling the XENMEM_decrease_reservation hypercall to give back memory pages to Xen, might be able to retain access to those pages even after Xen started reusing them for other purposes.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-5117-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
xen (PTS)	jessie, jessie (lts)	4.4.4lts5-0+deb8u1	vulnerable
	stretch (security), stretch (lts), stretch	4.8.5.final+shim4.10.4-1+deb9u12	fixed
	buster (security), buster, buster (lts)	4.11.4+107-gef32c7afa2-1	fixed
	bullseye	4.14.6-1	fixed
	bullseye (security)	4.14.5+94-ge49571868d-1	fixed
	bookworm	4.17.3+10-g091466ba55-1~deb12u1	fixed
	sid, trixie	4.17.3+36-g54dacb5c02-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin
xen	source	jessie	(unfixed)	end-of-life
xen	source	stretch	(not affected)
xen	source	buster	(not affected)
xen	source	bullseye	4.14.4+74-gd7b22226b5-1		DSA-5117-1
xen	source	(unstable)	4.16.0+51-g0941d6cb-1

Notes

[buster] - xen <not-affected> (Vulnerable code introduced later)
[stretch] - xen <not-affected> (Vulnerable code introduced later)
https://xenbits.xen.org/xsa/advisory-393.html