tty: Flush tty buffers after hardware shutdown
The line discipline buffer and the tty buffers must be flushed again
after hardware shutdown; otherwise, a brief window exists between the
ldisc flush in tty_port_close_start() and the subsequent
tty_port_shutdown(), during which more data could be received into the
tty buffers. A racing open might then be able to receive data from the
previous session.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 3b641d1..4d9abaa 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -520,6 +520,7 @@
{
unsigned long flags;
+ tty_ldisc_flush(tty);
tty->closing = 0;
spin_lock_irqsave(&port->lock, flags);