Bug 2461560 (CVE-2026-31553)

Summary:	CVE-2026-31553 kernel: KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	rhel-process-autobot, 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 (Kernel-based Virtual Machine) component. Specifically, in the ARM64 architecture, an incorrect calculation of the descriptor address in the `__kvm_at_swap_desc()` function could lead to memory corruption. This vulnerability may allow an attacker to cause system instability or affect the integrity of virtual machines.	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 2026-04-24 15:08:30 UTC

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

KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()

Using "(u64 __user *)hva + offset" to get the virtual addresses of S1/S2
descriptors looks really wrong, if offset is not zero. What we want to get
for swapping is hva + offset, not hva + offset*8. ;-)

Fix it.

Comment 1 Keith Grant 2026-04-24 17:15:57 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042456-CVE-2026-31553-0d39@gregkh/T