Bug 2467009 (CVE-2026-43103)

Summary:	CVE-2026-43103 kernel: net: lapbether: handle NETDEV_PRE_TYPE_CHANGE
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's `lapbether` network driver. This vulnerability occurs because the `lapbeth_data_transmit()` function expects a specific underlying device type, and without proper handling of network device type changes, this expectation can be violated. This could lead to unexpected behavior or system instability, potentially resulting in 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 2026-05-06 10:03:00 UTC

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

net: lapbether: handle NETDEV_PRE_TYPE_CHANGE

lapbeth_data_transmit() expects the underlying device type
to be ARPHRD_ETHER.

Returning NOTIFY_BAD from lapbeth_device_event() makes sure
bonding driver can not break this expectation.

Comment 1 Alexander B 2026-05-06 14:08:37 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050622-CVE-2026-43103-85e9@gregkh/T