In v_recv_cmd_submit(), urb_p->urb->pipe has the type unsigned int
(which is 32-bit long on x86_64) but 11<<30 results in a 34-bit integer.
Therefore the 2 leading bits are truncated and
urb_p->urb->pipe &= ~(11 << 30);
has the same meaning as
urb_p->urb->pipe &= ~(3 << 30);
This second statement seems to be how the code was intended to be
written, as PIPE_ constants have values between 0 and 3.
The overflow has been detected with a clang warning:
drivers/usb/usbip/vudc_rx.c:145:27: warning: signed shift result
(0x2C0000000) requires 35 bits to represent, but 'int' only has 32
bits [-Wshift-overflow]
urb_p->urb->pipe &= ~(11 << 30);
~~ ^ ~~