CVE-2025-40058 iommu/vt-d: Disallow dirty tracking if incoherent page walk
Improper IOMMU configuration allows non-recoverable faults when dirty tracking is enabled on incoherent page walks, causing system crashes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40058?
CVE-2025-40058 is a high-severity vulnerability in Linux, published on 28 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2025-40058?
How do I fix CVE-2025-40058?
Apply the vendor's patch.
Is CVE-2025-40058 being exploited?
There is no known exploitation of CVE-2025-40058 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40058, DEBIAN-CVE-2025-40058, GHSA-hwfw-95mf-c924, ROOT-OS-DEBIAN-13-CVE-2025-40058, ROOT-OS-UBUNTU-2404-CVE-2025-40058, UBUNTU-CVE-2025-40058.