CVE-2022-23033: Debian Linux
High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.
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.
Affected products
- Debian Debian Linux: version 11.0 only
- Fedoraproject Fedora: version 34 only
- Xen Xen: from 4.12.0
Published 2022-01-25. Last modified 2026-06-17.