CVE Catalog

CVE-2026-45945

HighCVSS 8.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel, a race condition was found in the Intel VT-d driver during PASID table entry replacement. Due to the 512-bit entry size, which hardware may read in smaller chunks, directly overwriting an active entry (with Present bit set) can lead to an inconsistent state, resulting in unpredictable behavior or spurious faults.

Risk Assessment

The organization is exposed to potential system crashes, IOMMU instability, and possible memory management errors, which could lead to service disruptions or data integrity violations.

Recommendation

Immediately update the Linux kernel to a version containing the fix that removes unsafe replacement helpers and implements a safe 'clear-then-update' flow.

Other vulnerabilities in Linux kernel

See all
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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS