CVE-2026-45945
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel related to a race condition during the replacement of a PASID entry in the Intel VT-d table. This issue may lead to unpredictable behavior of IOMMU hardware due to incomplete data reads.
Risk Assessment
Organizations may encounter data integrity issues and unpredictable hardware faults, potentially leading to system failures and data loss.
Recommendation
It is recommended to update the Linux kernel to a version that includes the fix eliminating unsafe replacement methods and to implement a safe update flow.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix race condition during PASID entry replacement The Intel VT-d PASID table entry is 512 bits (64 bytes). When replacing an active PASID entry (e.g., during domain replacement), the current implementation calculates a new entry on the stack and copies it to the table using a single structure assignment. struct pasid_entry *pte, new_pte; pte = intel_pasid_get_entry(dev, pasid); pasid_pte_config_first_level(iommu, &new_pte, ...); *pte = new_pte; Because the hardware may fetch the 512-bit PASID entry in multiple 128-bit chunks, updating the entire entry while it is active (Present bit set) risks a "torn" read. In this scenario, the IOMMU hardware could observe an inconsistent state — partially new data and partially old data — leading to unpredictable behavior or spurious faults. Fix this by removing the unsafe "replace" helpers and following the "clear-then-update" flow, which ensures the Present bit is cleared and the required invalidation handshake is completed before the new configuration is applied.