Bug 2467121 (CVE-2026-43228)

Summary:	CVE-2026-43228 kernel: hfs: Replace BUG_ON with error handling for CNID count checks
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
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 HFS component. A local attacker could provide a specially crafted and corrupted Master Directory Block (MDB) to trigger a kernel panic. This vulnerability, caused by improper error handling of CNID count checks, leads to a system 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 2026-05-06 13:05:24 UTC

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

hfs: Replace BUG_ON with error handling for CNID count checks

In a06ec283e125 next_id, folder_count, and file_count in the super block
info were expanded to 64 bits, and BUG_ONs were added to detect
overflow. This triggered an error reported by syzbot: if the MDB is
corrupted, the BUG_ON is triggered. This patch replaces this mechanism
with proper error handling and resolves the syzbot reported bug.

Singed-off-by: Jori Koolstra <jkoolstra>

Comment 1 Keith Grant 2026-05-06 22:21:02 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050655-CVE-2026-43228-4b65@gregkh/T