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().