LAPB over Ethernet Type Change Handling in Linux Kernel

Publication date: 2026-05-06

Last updated on: 2026-06-01

Assigner: kernel.org

Description

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.

CVSS Scores

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Meta Information

Published

2026-05-06

Last Modified

2026-06-01

Generated

2026-07-06

AI Q&A

2026-05-06

EPSS Evaluated

2026-07-05

NVD

CVE-2026-43103

EUVD

EUVD-2026-27616

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	From 6.13 (inc) to 6.18.24 (exc)
linux	linux_kernel	From 6.19 (inc) to 6.19.14 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.83 (exc)
linux	linux_kernel	From 2.6.24 (inc) to 6.6.136 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves the lapbether network driver. Specifically, the function lapbeth_data_transmit() expects the underlying device type to be ARPHRD_ETHER (Ethernet). The issue was that without proper handling of the NETDEV_PRE_TYPE_CHANGE event, this expectation could be broken. The fix ensures that returning NOTIFY_BAD from lapbeth_device_event() prevents the bonding driver from violating this expectation.

Impact Analysis

If the lapbeth_data_transmit() function's expectation about the device type is broken, it could lead to improper handling of network data transmission in bonded network interfaces. This might cause network communication issues or instability in systems relying on the lapbether driver and bonding functionality.

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