net: phy: Don't register LEDs for genphy

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: net: phy: Don't register LEDs for genphy If a PHY has no driver, the genphy driver is probed/removed directly in phy_attach/detach. If the PHY's ofnode has an "leds" subnode, then the LEDs will be (un)registered when probing/removing the genphy driver. This could occur if the leds are for a non-generic driver that isn't loaded for whatever reason. Synchronously removing the PHY device in phy_detach leads to the following deadlock: rtnl_lock() ndo_close() ... phy_detach() phy_remove() phy_leds_unregister() led_classdev_unregister() led_trigger_set() netdev_trigger_deactivate() unregister_netdevice_notifier() rtnl_lock() There is a corresponding deadlock on the open/register side of things (and that one is reported by lockdep), but it requires a race while this one is deterministic. Generic PHYs do not support LEDs anyway, so don't bother registering them.

References

• https://git.kernel.org/stable/c/ec158d05eaa91b2809cab65f8068290e3c05ebdd
• https://git.kernel.org/stable/c/fd6493533af9e5d73d0d42ff2a8ded978a701dc6
• https://git.kernel.org/stable/c/75e1b2079ef0653a2f7aa69be515d86b7faf1908
• https://git.kernel.org/stable/c/f0f2b992d8185a0366be951685e08643aae17d6d