USB: serial: quatech2: fix use-after-free in probe error path

commit 028c49f5e02a257c94129cd815f7c8485f51d4ef upstream.

The interface read URB is submitted in attach, but was only unlinked by
the driver at disconnect.

In case of a late probe error (e.g. due to failed minor allocation),
disconnect is never called and we would end up with active URBs for an
unbound interface. This in turn could lead to deallocated memory being
dereferenced in the completion callback.

Fixes: f7a33e608d9a ("USB: serial: add quatech2 usb to serial driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c
index 504f5bff79c0c27d3171de45da2b8678fd0acc03..b18974cbd9950dce2c8b75dd6d02793f47e9d7ef 100644 (file)
--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -141,6 +141,7 @@ static void qt2_release(struct usb_serial *serial)
 
        serial_priv = usb_get_serial_data(serial);
 
+       usb_kill_urb(serial_priv->read_urb);
        usb_free_urb(serial_priv->read_urb);
        kfree(serial_priv->read_buffer);
        kfree(serial_priv);