Bug 2541162 (CVE-2026-98057)

Summary:	CVE-2026-98057 kernel: ring-buffer: Add checking nr_subbufs to persistent ring buffer validation
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 tracing ring buffer. The persistent ring buffer validation logic fails to verify that the recorded sub-buffer count matches the expected page count in the metadata. A local attacker capable of manipulating persistent memory metadata could exploit this issue to induce out-of-bounds memory operations, potentially leading to memory corruption or a Denial of Service (DoS).	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 2026-09-25 10:53:46 UTC

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

ring-buffer: Add checking nr_subbufs to persistent ring buffer validation

Sashiko reported that the code was using meta->nr_subbufs without making
sure that it matched the nr_pages + 1 on data that was assuming the two
were the same.

Add a check to the persistent ring buffer validation code to make sure
that the saved nr_subbufs matches what we expect.

Comment 1 Keith Grant 2026-09-28 23:51:02 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98057.mbox