Bug 2516259 (CVE-2026-72277)

Summary:	CVE-2026-72277 kernel: KVM: arm64: nv: Inject SEA if guest VNCR isn't normal memory
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:	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) for ARM64 systems. When KVM constructs an L1 VNCR (Virtual Nested Control Register) mapping, it incorrectly applies cacheable memory attributes even when the underlying physical memory is not normal memory. This can lead to a system error (SError) during writeback operations, potentially causing system instability or a denial of service.	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 2026-08-15 06:03:07 UTC

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

KVM: arm64: nv: Inject SEA if guest VNCR isn't normal memory

When constructing an L1 VNCR mapping, KVM unconditionally uses cacheable
memory attributes, even if the underlying PFN isn't memory. This gets
particularly hairy if the endpoint doesn't support cacheable memory
attributes, potentially throwing an SError on writeback...

While KVM does permit cacheable memory attributes on certain PFNMAP
VMAs, kvm_translate_vncr() isn't currently grabbing the VMA. So do the
simpler thing for now and just reject everything that isn't memory.

Comment 1 gkamathe 2026-08-17 14:22:39 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081558-CVE-2026-72277-a7f8@gregkh/T