The current setup of the quarantine page tables assumes that the
quarantine domain (dom_io) has been initialized with an address width
of DEFAULT_DOMAIN_ADDRESS_WIDTH (48) and hence 4 page table levels.

However dom_io being a PV domain gets the AMD-Vi IOMMU page tables
levels based on the maximum (hot pluggable) RAM address, and hence on
systems with no RAM above the 512GB mark only 3 page-table levels are
configured in the IOMMU.

On systems without RAM above the 512GB boundary
amd_iommu_quarantine_init() will setup page tables for the scratch
page with 4 levels, while the IOMMU will be configured to use 3 levels
only, resulting in the last page table directory (PDE) effectively
becoming a page table entry (PTE), and hence a device in quarantine
mode gaining write access to the page destined to be a PDE.

Due to this page table level mismatch, the sink page the device gets
read/write access to is no longer cleared between device assignment,
possibly leading to data leaks.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

Not passing through physical devices to guests will avoid the vulnerability. Not using quarantine scratch-page mode will avoid the vulnerability, but could result in other issues.

History

Tue, 17 Jun 2025 16:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-787
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: XEN

Published:

Updated: 2025-06-17T16:11:08.422Z

Reserved: 2023-10-27T07:55:35.331Z

Link: CVE-2023-46835

cve-icon Vulnrichment

Updated: 2024-08-02T20:53:21.879Z

cve-icon NVD

Status : Modified

Published: 2024-01-05T17:15:11.147

Modified: 2025-06-17T16:15:23.800

Link: CVE-2023-46835

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.