CVE-2025-39805

/// Technical description

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

net: macb: fix unregister_netdev call order in macb_remove()

When removing a macb device, the driver calls phy_exit() before

unregister_netdev(). This leads to a WARN from kernfs:

------------[ cut here ]------------

kernfs: can not remove 'attached_dev', no directory

WARNING: CPU: 1 PID: 27146 at fs/kernfs/dir.c:1683

Call trace:

kernfs_remove_by_name_ns+0xd8/0xf0

sysfs_remove_link+0x24/0x58

phy_detach+0x5c/0x168

phy_disconnect+0x4c/0x70

phylink_disconnect_phy+0x6c/0xc0 [phylink]

macb_close+0x6c/0x170 [macb]

...

macb_remove+0x60/0x168 [macb]

platform_remove+0x5c/0x80

...

The warning happens because the PHY is being exited while the netdev

is still registered. The correct order is to unregister the netdev

before shutting down the PHY and cleaning up the MDIO bus.

Fix this by moving unregister_netdev() ahead of phy_exit() in

macb_remove().

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References