CVE-2026-43219: net: cpsw_new: Fix potential unregister of netdev that has not been registered yet
In the Linux kernel, the following vulnerability has been resolved:
net: cpswnew: Fix potential unregister of netdev that has not been registered yet
If an error occurs during registernetdev() for the first MAC in cpswregisterports(), even though cpsw->slaves[0].ndev is set to NULL, cpsw->slaves[1].ndev would remain unchanged. This could later cause cpswunregisterports() to attempt unregistering the second MAC. To address this, add a check for ndev->regstate before calling unregisternetdev(). With this change, setting cpsw->slaves[i].ndev to NULL becomes unnecessary and can be removed accordingly.
Affected Software
Event History
Frequently Asked Questions
What conditions are required to trigger this issue?
A local user with low privileges must cause an error during register_netdev() for the first MAC while the cpsw_new driver is registering ports. The failure can subsequently lead cleanup code to attempt to unregister the second MAC even though it was not registered.
What is the practical impact?
The issue affects availability only: the CVSS vector reports no confidentiality or integrity impact and a high availability impact. It is rated medium severity with a CVSS 3.1 score of 5.5.
Which systems are exposed?
Systems running the Linux kernel with the cpsw_new network driver are relevant. The provided information does not identify affected kernel versions, hardware platforms, or whether the driver is enabled by default.
What mitigation is described if an update cannot be applied immediately?
No workaround or configuration-based mitigation is provided. The documented fix adds a netdev registration-state check before unregister_netdev() is called.