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

usb: xhci: prevent potential failure in handle_tx_event() for Transfer events without TRB

Some transfer events don't always point to a TRB, and consequently don't
have a endpoint ring. In these cases, function handle_tx_event() should
not proceed, because if 'ep->skip' is set, the pointer to the endpoint
ring is used.

To prevent a potential failure and make the code logical, return after
checking the completion code for a Transfer event without TRBs.