Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932433Ab3DVOvx (ORCPT ); Mon, 22 Apr 2013 10:51:53 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51394 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754229Ab3DVO31 (ORCPT ); Mon, 22 Apr 2013 10:29:27 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Greg Kroah-Hartman" , "Johan Hovold" Date: Mon, 22 Apr 2013 15:25:59 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [11/75] USB: mos7840: fix use-after-free in TIOCMIWAIT In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:6834:ff73:7553:7f84 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 Content-Length: 2645 Lines: 75 3.2.44-rc1 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 && -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/