CVE-2025-40058 — iommu/vt-d: Disallow dirty tracking if incoherent page walk
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 atomica…
Published: 2025-10-28 · CVSS: 8.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7