Code:  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);
 }

Vulnerability Type: DoS 
CWE ID: CWE-404
Summary: The omninet_open function in drivers/usb/serial/omninet.c in the Linux kernel before 4.10.4 allows local users to cause a denial of service (tty exhaustion) by leveraging reference count mishandling.
Commit Message: USB: serial: omninet: fix reference leaks at open

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@vger.kernel.org>	# 2.6.28
Signed-off-by: Johan Hovold <johan@kernel.org>