CVE-2026-45862

A flaw was found in the Linux kernel's IOMMU (Input/Output Memory Management Unit) virtualized directed I/O (VT-d) component. When a freshly allocated PASID (Process Address Space ID) table is written to a directory entry, the CPU cache flush for this table occurs too late. This creates a time window where non-coherent IOMMU hardware might use the PASID table while its contents in memory are still uninitialized or contain old, random data. This could lead to data integrity issues or system instability.

This vulnerability is rated as having a Moderate impact by Red Hat because exploitation requires local access on systems operating with non-coherent Intel VT-d hardware supporting Process Address Space ID (PASID), with consequences limited to denial of service or memory corruption. The timing window for unsynchronized cache lines arises specifically during dynamic PASID directory initialization. Deployments not utilizing scalable-mode Intel IOMMU features or running on coherent architectures are not exposed to this issue.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.