Bug 2516407 (CVE-2026-72236)

Summary:	CVE-2026-72236 kernel: s390/perf_cpum_cf: Add missing array_index_nospec() to __hw_perf_event_init()
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 s390 performance monitoring component (`s390/perf_cpum_cf`). A userspace-controlled variable was used as an array index without proper speculation barriers. This could allow a local attacker to potentially exploit speculative execution, leading to information disclosure.	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 06:10:50 UTC

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

s390/perf_cpum_cf: Add missing array_index_nospec() to __hw_perf_event_init()

ev variable is userspace controlled via event->attr.config and used
as an array index after bounds checking, but without speculation
barriers.

Add the missing array_index_nospec() call to prevent speculative
execution.

Comment 1 gkamathe 2026-08-18 09:15:23 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081550-CVE-2026-72236-5d4f@gregkh/T