In the Linux kernel, the following vulnerability has been resolved:

iommu/vt-d: Disallow dirty tracking if incoherent page walk

Dirty page tracking relies on the IOMMU atomically updating the dirty bit
in the paging-structure entry. For this operation to succeed, the paging-
structure memory must be coherent between the IOMMU and the CPU. In
another word, if the iommu page walk is incoherent, dirty page tracking
doesn't work.

The Intel VT-d specification, Section 3.10 "Snoop Behavior" states:

"Remapping hardware encountering the need to atomically update A/EA/D bits
in a paging-structure entry that is not snooped will result in a non-
recoverable fault."

To prevent an IOMMU from being incorrectly configured for dirty page
tracking when it is operating in an incoherent mode, mark SSADS as
supported only when both ecap_slads and ecap_smpwc are supported.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 28 Oct 2025 12:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Disallow dirty tracking if incoherent page walk Dirty page tracking relies on the IOMMU atomically updating the dirty bit in the paging-structure entry. For this operation to succeed, the paging- structure memory must be coherent between the IOMMU and the CPU. In another word, if the iommu page walk is incoherent, dirty page tracking doesn't work. The Intel VT-d specification, Section 3.10 "Snoop Behavior" states: "Remapping hardware encountering the need to atomically update A/EA/D bits in a paging-structure entry that is not snooped will result in a non- recoverable fault." To prevent an IOMMU from being incorrectly configured for dirty page tracking when it is operating in an incoherent mode, mark SSADS as supported only when both ecap_slads and ecap_smpwc are supported.
Title iommu/vt-d: Disallow dirty tracking if incoherent page walk
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-28T11:48:31.567Z

Reserved: 2025-04-16T07:20:57.158Z

Link: CVE-2025-40058

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-28T12:15:40.150

Modified: 2025-10-28T12:15:40.150

Link: CVE-2025-40058

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.