Bug 2552219 (CVE-2026-98387)

Summary:	CVE-2026-98387 kernel: s390/crypto: Fix skcipher_walk return code handling in aes_s390
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
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 s390 cryptographic subsystem. Missing error code verification during AES (Advanced Encryption Standard) cipher operations allows data processing loops to execute even if setup fails. A local user could exploit this vulnerability during cryptographic operations to cause the system to access uninitialized memory, leading to a Denial of Service (DoS) via a kernel crash or potential 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 2026-10-14 13:48:13 UTC

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

s390/crypto: Fix skcipher_walk return code handling in aes_s390

The return codes from skcipher_walk_virt() were not properly checked
before entering the processing loops in ecb_aes_crypt() and ctr_aes_crypt().
If skcipher_walk_virt() fails, the walk structure may be in an undefined
state, and attempting to process data could lead to incorrect behavior
or accessing uninitialized memory.

Add proper return code checking to ensure correct handling of the walk
initialization and walk advance and eventually return to the caller
with that return code.

Comment 1 Mauro Matteo Cascella 2026-10-15 10:04:41 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98387.mbox