tty: USB hangup is racy

The USB layer uses tty_hangup to deal with unplugs of the physical hardware
(analogous to loss of carrier) and then frees the resources. However the
tty_hangup is asynchronous. As the hangup can sleep we can use tty_vhangup
which is the non async version to avoid freeing resources too early.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Cox 2009-09-19 13:13:23 -07:00 committed by Live-CD User
parent 9b80fee149
commit d2b391822a

View file

@ -1161,10 +1161,7 @@ void usb_serial_disconnect(struct usb_interface *interface)
if (port) {
struct tty_struct *tty = tty_port_tty_get(&port->port);
if (tty) {
/* The hangup will occur asynchronously but
the object refcounts will sort out all the
cleanup */
tty_hangup(tty);
tty_vhangup(tty);
tty_kref_put(tty);
}
kill_traffic(port);