Bug 2482096 (CVE-2026-45862)

Summary:	CVE-2026-45862 kernel: iommu/vt-d: Flush cache for PASID table before using it
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	---
Doc Text:	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.	Story Points:	---
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Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-27 15:11:08 UTC

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.

Comment 1 Keith Grant 2026-05-28 04:06:49 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052711-CVE-2026-45862-6bdd@gregkh/T