Bug 2532174 (CVE-2026-89448)

Summary:	CVE-2026-89448 kernel: iommu/vt-d: Force requesting ACS when tboot is enabled
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's IOMMU (Input/Output Memory Management Unit) component. When tboot (Trusted Boot) is enabled, the system may fail to correctly request Access Control Services (ACS). This misconfiguration could potentially lead to a bypass of intended Access Control Services, which are designed to enforce security policies for I/O devices.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-11 21:06:47 UTC

In the Linux kernel, the following vulnerability has been resolved:

iommu/vt-d: Force requesting ACS when tboot is enabled

Currently the conditions of requesting ACS in detect_intel_iommu()
don't include tboot, leading to a possible misconfiguration with ACS
disabled (e.g. due to user opts) while iommu is later forced on by
tboot_force_iommu().

Fix it by checking tboot in detect_intel_iommu().

Comment 1 Mauro Matteo Cascella 2026-09-17 18:29:21 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89448.mbox