From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757657Ab3CYBgY (ORCPT ); Sun, 24 Mar 2013 21:36:24 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33859 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755641Ab3CYBPW (ORCPT ); Sun, 24 Mar 2013 21:15:22 -0400 Message-Id: <20130325010533.545129349@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 25 Mar 2013 01:06:57 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Johan Hovold , Greg Kroah-Hartman Subject: [ 093/104] USB: mos7840: fix use-after-free in TIOCMIWAIT Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In-Reply-To: <20130325010524.240972766@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:f137:78a:b654:affb X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit a14430db686b8e459e1cf070a6ecf391515c9ab9 upstream. Use the port wait queue and make sure to check the serial disconnected flag before accessing private port data after waking up. This is is needed as the private port data (including the wait queue itself) can be gone when waking up after a disconnect. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/usb/serial/mos7840.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/drivers/usb/serial/mos7840.c +++ b/drivers/usb/serial/mos7840.c @@ -240,7 +240,6 @@ struct moschip_port { char open; char open_ports; wait_queue_head_t wait_chase; /* for handling sleeping while waiting for chase to finish */ - wait_queue_head_t delta_msr_wait; /* for handling sleeping while waiting for msr change to happen */ int delta_msr_cond; struct async_icount icount; struct usb_serial_port *port; /* loop back to the owner of this object */ @@ -455,7 +454,7 @@ static void mos7840_handle_new_msr(struc } mos7840_port->delta_msr_cond = 1; - wake_up_interruptible(&mos7840_port->delta_msr_wait); + wake_up_interruptible(&port->port->delta_msr_wait); } } @@ -1118,7 +1117,6 @@ static int mos7840_open(struct tty_struc /* initialize our wait queues */ init_waitqueue_head(&mos7840_port->wait_chase); - init_waitqueue_head(&mos7840_port->delta_msr_wait); /* initialize our icount structure */ memset(&(mos7840_port->icount), 0x00, sizeof(mos7840_port->icount)); @@ -2285,13 +2283,18 @@ static int mos7840_ioctl(struct tty_stru while (1) { /* interruptible_sleep_on(&mos7840_port->delta_msr_wait); */ mos7840_port->delta_msr_cond = 0; - wait_event_interruptible(mos7840_port->delta_msr_wait, - (mos7840_port-> + wait_event_interruptible(port->delta_msr_wait, + (port->serial->disconnected || + mos7840_port-> delta_msr_cond == 1)); /* see if a signal did it */ if (signal_pending(current)) return -ERESTARTSYS; + + if (port->serial->disconnected) + return -EIO; + cnow = mos7840_port->icount; smp_rmb(); if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&