Affected: Linux

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

net: usb: kaweth: remove TX queue manipulation in kaweth_set_rx_mode

kaweth_set_rx_mode(), the ndo_set_rx_mode callback, calls netif_stop_queue() and netif_wake_queue(). These are TX queue flow control functions unrelated to RX multicast configuration.

The premature netif_wake_queue() can re-enable TX while tx_urb is still in-flight, leading to a double usb_submit_urb() on the same URB:

kaweth_start_xmit() { netif_stop_queue(); usb_submit_urb(kaweth->tx_urb); }

kaweth_set_rx_mode() { netif_stop_queue(); netif_wake_queue(); // wakes TX queue before URB is done }

kaweth_start_xmit() { netif_stop_queue(); usb_submit_urb(kaweth->tx_urb); // URB submitted while active }

This triggers the WARN in usb_submit_urb():

"URB submitted while active"

This is a similar class of bug fixed in rtl8150 by

- commit 958baf5eaee3 ("net: usb: Remove disruptive netif_wake_queue in rtl8150_set_multicast").

Also kaweth_set_rx_mode() is already functionally broken, the real set_rx_mode action is performed by kaweth_async_set_rx_mode(), which in turn is not a no-op only at ndo_open() time.