CVE-2025-38537
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
16/08/2025
Last modified:
18/08/2025
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
net: phy: Don&#39;t register LEDs for genphy<br />
<br />
If a PHY has no driver, the genphy driver is probed/removed directly in<br />
phy_attach/detach. If the PHY&#39;s ofnode has an "leds" subnode, then the<br />
LEDs will be (un)registered when probing/removing the genphy driver.<br />
This could occur if the leds are for a non-generic driver that isn&#39;t<br />
loaded for whatever reason. Synchronously removing the PHY device in<br />
phy_detach leads to the following deadlock:<br />
<br />
rtnl_lock()<br />
ndo_close()<br />
...<br />
phy_detach()<br />
phy_remove()<br />
phy_leds_unregister()<br />
led_classdev_unregister()<br />
led_trigger_set()<br />
netdev_trigger_deactivate()<br />
unregister_netdevice_notifier()<br />
rtnl_lock()<br />
<br />
There is a corresponding deadlock on the open/register side of things<br />
(and that one is reported by lockdep), but it requires a race while this<br />
one is deterministic.<br />
<br />
Generic PHYs do not support LEDs anyway, so don&#39;t bother registering<br />
them.