Intel VT-d PASID Table Cache Flush Vulnerability

Publication date: 2026-05-27

Last updated on: 2026-06-25

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Flush cache for PASID table before using it When writing the address of a freshly allocated zero-initialized PASID table to a PASID directory entry, do that after the CPU cache flush for this PASID table, not before it, to avoid the time window when this PASID table may be already used by non-coherent IOMMU hardware while its contents in RAM is still some random old data, not zero-initialized.

CVSS Scores

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Meta Information

Published

2026-05-27

Last Modified

2026-06-25

Generated

2026-07-07

AI Q&A

2026-05-27

EPSS Evaluated

2026-07-05

NVD

CVE-2026-45862

EUVD

EUVD-2026-32328

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 5.4.237 (inc) to 5.5 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.14 (exc)
linux	linux_kernel	From 6.19 (inc) to 6.19.4 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.75 (exc)
linux	linux_kernel	From 5.10.175 (inc) to 5.10.252 (exc)
linux	linux_kernel	From 5.15.103 (inc) to 5.15.202 (exc)
linux	linux_kernel	From 6.1.16 (inc) to 6.1.165 (exc)
linux	linux_kernel	From 6.2.3 (inc) to 6.6.128 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's iommu/vt-d component. It involves the improper order of operations when handling a PASID (Process Address Space ID) table. Specifically, the CPU cache flush for a freshly allocated zero-initialized PASID table was done after writing its address to a PASID directory entry, rather than before. This creates a time window where non-coherent IOMMU hardware might use the PASID table while its contents in RAM still contain random old data instead of being zero-initialized, potentially leading to incorrect or unexpected behavior.

Impact Analysis

The vulnerability can lead to the use of stale or uninitialized data in the PASID table by the IOMMU hardware. This may cause unpredictable system behavior, potential data corruption, or security issues related to memory management and device isolation. Since the PASID table controls address translations for devices, improper initialization could affect system stability or security in environments relying on IOMMU for device isolation.

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