[PATCH -next 3/3] tty: Flush tty buffers after hardware shutdown

From: Peter Hurley
Date: Wed Nov 05 2014 - 12:40:52 EST


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@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/tty_port.c | 1 +
1 file changed, 1 insertion(+)

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 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
{
unsigned long flags;

+ tty_ldisc_flush(tty);
tty->closing = 0;

spin_lock_irqsave(&port->lock, flags);
--
2.1.3

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