Bug 2508480 (CVE-2026-64558)

Summary:	CVE-2026-64558 kernel: s390/pkey: Check length in pkey_pckmo handler implementation
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
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, specifically within the s390/pkey component. This vulnerability occurs because the `pkey_pckmo` handler function does not explicitly check the length of the target buffer. If the generated output data exceeds the provided buffer's length, the handler function fails. This could allow a local attacker to cause 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 2026-07-29 17:01:32 UTC

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

s390/pkey: Check length in pkey_pckmo handler implementation

Explicitly check the length of the target buffer in the pkey_pckmo
implementation of the key_to_protkey() handler function. The handler
function fails, if the generated output data exceeds the length of the
provided target buffer.

Comment 1 TEJ RATHI 2026-07-30 02:59:59 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072912-CVE-2026-64558-7352@gregkh/T