Bug 2532521 (CVE-2026-89727)

Summary:	CVE-2026-89727 kernel: KVM: arm64: GICv2: Don't WARN on out-of-range GICV_DIR INTID
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 Kernel-based Virtual Machine (KVM) for ARM64 (arm64) architecture. A malicious guest operating system can provide an interrupt ID (INTID) that is outside the expected range to the GICv2 (Generic Interrupt Controller version 2) during interrupt deactivation. This can trigger a warning condition in the host kernel, potentially leading to a host system crash and resulting in a Denial of Service (DoS) for the host.	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 2026-09-11 23:38:47 UTC

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

KVM: arm64: GICv2: Don't WARN on out-of-range GICV_DIR INTID

vgic_v2_deactivate() passes the INTID a guest wrote to GICV_DIR straight
to vgic_get_vcpu_irq(), and treats a failed lookup as a "can't happen"
condition with WARN_ON_ONCE().

The guest can make it happen at will, though: for any INTID outside of
the implemented SGI, PPI and SPI ranges the lookup returns NULL, since
GICv2 has no LPIs. A guest running with EOImode==1 writing such an INTID
to GICV_DIR triggers the WARN, and panics hosts running with
panic_on_warn.

Drop the WARN and ignore failed lookups.

Comment 1 gkamathe 2026-09-15 08:15:39 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89727.mbox