CVE-2022-23033 Information

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.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

https://xenbits.xenproject.org/xsa/advisory-393.txt http://www.openwall.com/lists/oss-security/2022/01/25/2 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OMR6UBGJW6JKND7IILGQ2CU35EQPF3E3/ https://www.debian.org/security/2022/dsa-5117

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8