Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965232AbaDJDXw (ORCPT ); Wed, 9 Apr 2014 23:23:52 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41105 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934776AbaDJDWV (ORCPT ); Wed, 9 Apr 2014 23:22:21 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold , Ben Hutchings , Yang Yingliang Subject: [PATCH 3.4 066/134] USB: mos7840: fix use-after-free in TIOCMIWAIT Date: Wed, 9 Apr 2014 20:23:02 -0700 Message-Id: <20140410032308.565369424@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140410032259.587501440@linuxfoundation.org> References: <20140410032259.587501440@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-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: Ben Hutchings Cc: Yang Yingliang Signed-off-by: Greg Kroah-Hartman --- 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); } } @@ -1116,7 +1115,6 @@ 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/