Bug 2540528 (CVE-2026-97423)

Summary:	CVE-2026-97423 kernel: cxl/region: Validate partition index before array access
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 Compute Express Link (CXL) subsystem. This vulnerability allows a local user to cause a Denial of Service (DoS) or system instability through an out-of-bounds memory access. During CXL region configuration, the kernel fails to validate that the partition index is non-negative before indexing an internal array, resulting in an out-of-bounds read if the partition is unresolved.	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 2026-09-24 17:07:47 UTC

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

cxl/region: Validate partition index before array access

construct_region() reads cxled->part and uses it to index
cxlds->part[] without checking for a negative value. If the
partition was never resolved, part remains at its initial value
of -1, causing an out-of-bounds array access.

Add a guard to return -EBUSY when part is negative.

The check was dropped during a merge.

Comment 1 Mauro Matteo Cascella 2026-09-29 11:28:40 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97423.mbox