From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758767AbcAKGp2 (ORCPT ); Mon, 11 Jan 2016 01:45:28 -0500 Received: from mail-pa0-f53.google.com ([209.85.220.53]:33297 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758613AbcAKGmD (ORCPT ); Mon, 11 Jan 2016 01:42:03 -0500 From: Peter Hurley To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-kernel@vger.kernel.org, Peter Hurley , stable@vger.kernel.org Subject: [PATCH v3 07/19] n_tty: Fix unsafe reference to "other" ldisc Date: Sun, 10 Jan 2016 22:40:56 -0800 Message-Id: <1452494468-21359-8-git-send-email-peter@hurleysoftware.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1452494468-21359-1-git-send-email-peter@hurleysoftware.com> References: <1452400870-6005-1-git-send-email-peter@hurleysoftware.com> <1452494468-21359-1-git-send-email-peter@hurleysoftware.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Although n_tty_check_unthrottle() has a valid ldisc reference (since the tty core gets the ldisc ref in tty_read() before calling the line discipline read() method), it does not have a valid ldisc reference to the "other" pty of a pty pair. Since getting an ldisc reference for tty->link essentially open-codes tty_wakeup(), just replace with the equivalent tty_wakeup(). Cc: Signed-off-by: Peter Hurley --- drivers/tty/n_tty.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index e09fd58..90eca26 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -269,16 +269,13 @@ static void n_tty_check_throttle(struct tty_struct *tty) static void n_tty_check_unthrottle(struct tty_struct *tty) { - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->link->ldisc->ops->write_wakeup == n_tty_write_wakeup) { + if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) return; if (!tty->count) return; n_tty_kick_worker(tty); - n_tty_write_wakeup(tty->link); - if (waitqueue_active(&tty->link->write_wait)) - wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT); + tty_wakeup(tty->link); return; } -- 2.7.0