USB: serial: ti_usb_3410_5052: fix TIOCSSERIAL permission check

Changing the port closing-wait parameter is a privileged operation so
make sure to return -EPERM if a regular user tries to change it.

Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index 4b497c1e850b19249bca038033e8856abd85c0df..bb50098a0ce66e48e82846f8d7823c556fccd937 100644 (file)
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -1418,14 +1418,19 @@ static int ti_set_serial_info(struct tty_struct *tty,
        struct serial_struct *ss)
 {
        struct usb_serial_port *port = tty->driver_data;
-       struct ti_port *tport = usb_get_serial_port_data(port);
+       struct tty_port *tport = &port->port;
        unsigned cwait;
 
        cwait = ss->closing_wait;
        if (cwait != ASYNC_CLOSING_WAIT_NONE)
                cwait = msecs_to_jiffies(10 * ss->closing_wait);
 
-       tport->tp_port->port.closing_wait = cwait;
+       if (!capable(CAP_SYS_ADMIN)) {
+               if (cwait != tport->closing_wait)
+                       return -EPERM;
+       }
+
+       tport->closing_wait = cwait;
 
        return 0;
 }