CVE-2022-23033

xen: arm: guest_physmap_remove_page not removing the p2m mappings (XSA-393)

Published Jan 25, 2022 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-5117-1 xen security update
EUVD EUVD EUVD-2022-28144 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.
History

No history.

Weaknesses

Sources

Status
PUBLISHED
Assigner
XEN
Published
Updated
Aug 3, 2024, 3:28 AM
Reserved
Jan 10, 2022, 12:00 AM
Status
Modified
Published
Jan 25, 2022, 2:15 PM
Modified
Jun 17, 2026, 4:29 AM
Severity
Moderate
Public date
Jan 25, 2022, 12:00 AM