USB: option close race

the option driver does not directly use usb_kill_urb(). It uses a wrapper.
This wrapper means that callbacks which are running are not killed during
close, resubmitting and illicitly pushing data into the tty layer.
The whole purpose of usb_kill_urb() is subverted. The wrapper must be removed.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Matthias Urlichs <smurf@smurf.noris.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/option.c

@@ -591,12 +591,6 @@ static int option_open(struct usb_serial_port *port, struct file *filp)
 	return (0);
 }
 
-static inline void stop_urb(struct urb *urb)
-{
-	if (urb && urb->status == -EINPROGRESS)
-		usb_kill_urb(urb);
-}
-
 static void option_close(struct usb_serial_port *port, struct file *filp)
 {
 	int i;
@@ -614,9 +608,9 @@ static void option_close(struct usb_serial_port *port, struct file *filp)
 
 		/* Stop reading/writing urbs */
 		for (i = 0; i < N_IN_URB; i++)
-			stop_urb(portdata->in_urbs[i]);
+			usb_kill_urb(portdata->in_urbs[i]);
 		for (i = 0; i < N_OUT_URB; i++)
-			stop_urb(portdata->out_urbs[i]);
+			usb_kill_urb(portdata->out_urbs[i]);
 	}
 	port->tty = NULL;
 }
@@ -747,9 +741,9 @@ static void option_shutdown(struct usb_serial *serial)
 		port = serial->port[i];
 		portdata = usb_get_serial_port_data(port);
 		for (j = 0; j < N_IN_URB; j++)
-			stop_urb(portdata->in_urbs[j]);
+			usb_kill_urb(portdata->in_urbs[j]);
 		for (j = 0; j < N_OUT_URB; j++)
-			stop_urb(portdata->out_urbs[j]);
+			usb_kill_urb(portdata->out_urbs[j]);
 	}
 
 	/* Now free them */