Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751060AbaDJEKV (ORCPT ); Thu, 10 Apr 2014 00:10:21 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:41099 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934756AbaDJDWT (ORCPT ); Wed, 9 Apr 2014 23:22:19 -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 3.4 064/134] USB: mct_u232: fix use-after-free in TIOCMIWAIT Date: Wed, 9 Apr 2014 20:23:00 -0700 Message-Id: <20140410032308.310847656@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 cf1d24443677a0758cfa88ca40f24858b89261c0 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 [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings Cc: Yang Yingliang Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/mct_u232.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) --- a/drivers/usb/serial/mct_u232.c +++ b/drivers/usb/serial/mct_u232.c @@ -126,8 +126,6 @@ struct mct_u232_private { unsigned char last_msr; /* Modem Status Register */ unsigned int rx_flags; /* Throttling flags */ struct async_icount icount; - wait_queue_head_t msr_wait; /* for handling sleeping while waiting - for msr change to happen */ }; #define THROTTLED 0x01 @@ -407,7 +405,6 @@ static int mct_u232_startup(struct usb_s if (!priv) return -ENOMEM; spin_lock_init(&priv->lock); - init_waitqueue_head(&priv->msr_wait); usb_set_serial_port_data(serial->port[0], priv); init_waitqueue_head(&serial->port[0]->write_wait); @@ -631,7 +628,7 @@ static void mct_u232_read_int_callback(s tty_kref_put(tty); } #endif - wake_up_interruptible(&priv->msr_wait); + wake_up_interruptible(&port->delta_msr_wait); spin_unlock_irqrestore(&priv->lock, flags); exit: retval = usb_submit_urb(urb, GFP_ATOMIC); @@ -852,13 +849,17 @@ static int mct_u232_ioctl(struct tty_st cprev = mct_u232_port->icount; spin_unlock_irqrestore(&mct_u232_port->lock, flags); for ( ; ; ) { - prepare_to_wait(&mct_u232_port->msr_wait, + prepare_to_wait(&port->delta_msr_wait, &wait, TASK_INTERRUPTIBLE); schedule(); - finish_wait(&mct_u232_port->msr_wait, &wait); + finish_wait(&port->delta_msr_wait, &wait); /* see if a signal did it */ if (signal_pending(current)) return -ERESTARTSYS; + + if (port->serial->disconnected) + return -EIO; + spin_lock_irqsave(&mct_u232_port->lock, flags); cnow = mct_u232_port->icount; spin_unlock_irqrestore(&mct_u232_port->lock, flags); -- 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/