USB: serial: fix interface refcounting

Make sure the interface is not released before our serial device.

Note that drivers are still not allowed to access the interface in
any way that may interfere with another driver that may have gotten
bound to the same interface after disconnect returns.

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

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index a19ed74d770d73b016e69070cb27e282bbc21fad..2e70efa08b77121f5d248413a95b14ea79095dda 100644 (file)
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -151,6 +151,7 @@ static void destroy_serial(struct kref *kref)
                }
        }
 
+       usb_put_intf(serial->interface);
        usb_put_dev(serial->dev);
        kfree(serial);
 }
@@ -620,7 +621,7 @@ static struct usb_serial *create_serial(struct usb_device *dev,
        }
        serial->dev = usb_get_dev(dev);
        serial->type = driver;
-       serial->interface = interface;
+       serial->interface = usb_get_intf(interface);
        kref_init(&serial->kref);
        mutex_init(&serial->disc_mutex);
        serial->minor = SERIAL_TTY_NO_MINOR;