Bug 2482623 (CVE-2026-46238)

Summary:	CVE-2026-46238 kernel: batman-adv: stop caching unowned originator pointers in BAT IV
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
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 `batman-adv` module of the Linux kernel. The BAT IV protocol was caching unowned originator pointers, which could become invalid after purge handling. This could lead to the use of stale data, potentially causing unexpected system behavior or information corruption within the kernel.	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 2026-05-28 11:06:20 UTC

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

batman-adv: stop caching unowned originator pointers in BAT IV

BAT IV keeps the last-hop neighbor address in each neigh_node, but some
paths also cache an originator pointer derived from a temporary lookup.
That pointer is not owned by the neigh_node and may no longer refer to a
live originator entry after purge handling runs.

Stop storing the auxiliary originator pointer in the BAT IV neighbor
state. When BAT IV needs the neighbor originator data, resolve it from
the stored neighbor address and drop the reference again after use.

[sven: avoid bonding logic for outgoing OGM]

Comment 1 Keith Grant 2026-05-28 12:11:12 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052841-CVE-2026-46238-1c65@gregkh/T