[CVE-2017-8925][PATCH T/Y] USB: serial: omninet: fix reference leaks at open

[Po-Hsu Lin]

From: Johan Hovold <johan at kernel.org>

CVE-2017-8925

This driver needlessly took another reference to the tty on open, a
reference which was then never released on close. This lead to not just
a leak of the tty, but also a driver reference leak that prevented the
driver from being unloaded after a port had once been opened.

Fixes: 4a90f09b20f4 ("tty: usb-serial krefs")
Cc: stable <stable at vger.kernel.org>	# 2.6.28
Signed-off-by: Johan Hovold <johan at kernel.org>
(cherry picked from commit 30572418b445d85fcfe6c8fe84c947d2606767d8)

Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>
---
 drivers/usb/serial/omninet.c |    6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/usb/serial/omninet.c b/drivers/usb/serial/omninet.c
index f6c6900..880bbdb 100644
--- a/drivers/usb/serial/omninet.c
+++ b/drivers/usb/serial/omninet.c
@@ -129,12 +129,6 @@ static int omninet_port_remove(struct usb_serial_port *port)
 
 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
-	struct usb_serial	*serial = port->serial;
-	struct usb_serial_port	*wport;
-
-	wport = serial->port[1];
-	tty_port_tty_set(&wport->port, tty);
-
 	return usb_serial_generic_open(tty, port);
 }
 
-- 
1.7.9.5