Bug 2531066 (CVE-2026-80921)

Summary:	CVE-2026-80921 kernel: KVM: s390: vsie: zero stale crypto bits
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
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 KVM s390 Virtual Shared Inter-Partition Emulation (VSIE) component. When shadowing crypto access bits from a format0 apcb, stale crypto bits were not properly cleared. This oversight could allow a nested guest to potentially access a device that should no longer be available, leading to unauthorized information disclosure or access to resources.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
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 2026-09-09 16:41:14 UTC

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

KVM: s390: vsie: zero stale crypto bits

When shadowing crypto access bits from a format0 apcb (crycb 0 or 1),
the bits 64..255 are unchanged from whatever is in the vsie page in the
crycb and thus in the apcb. This gives a nested guest potential access
to a device no longer available. Zero out the remaining bits.

Comment 1 gkamathe 2026-09-10 06:06:55 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80921.mbox

Comment 5 Jon Orris 2026-10-05 10:48:56 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:75746 https://access.redhat.com/errata/RHSA-2026:75746

Comment 6 Jon Orris 2026-10-05 11:24:02 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:75747 https://access.redhat.com/errata/RHSA-2026:75747

Comment 7 Jon Orris 2026-10-07 20:28:51 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:76738 https://access.redhat.com/errata/RHSA-2026:76738

Comment 8 Jon Orris 2026-10-08 09:50:27 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:76739 https://access.redhat.com/errata/RHSA-2026:76739