USB: fix NULL pointer dereference on drivers/usb/serial/whiteheat.c

Am Sonntag, 16. Dezember 2007 05:23:47 schrieb Andrew Morton:
> On Sat, 15 Dec 2007 07:08:52 -0800 (PST) bugme-daemon@bugzilla.kernel.org wrote:
> 
> > http://bugzilla.kernel.org/show_bug.cgi?id=9573
 
> > There's a null pointer dereference on drivers/usb/serial/whiteheat.c as
> > follows:
> > 
> > (1) line 613:  the test "if (port->tty)" implies that null is a legal value
> >     for "port->tty" at that point
> > 
> > (2) neither firm_open nor firm_purge initialize "port->tty"

drivers/usb/serial/usb-serial::serial_open() sets port->tty
The check for NULL is bogus. This patch removes the check.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/whiteheat.c

@@ -610,8 +610,7 @@ static int whiteheat_open (struct usb_serial_port *port, struct file *filp)
 	if (retval)
 		goto exit;
 
-	if (port->tty)
-		port->tty->low_latency = 1;
+	port->tty->low_latency = 1;
 
 	/* send an open port command */
 	retval = firm_open(port);