Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965086Ab3DHKNp (ORCPT ); Mon, 8 Apr 2013 06:13:45 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42789 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935659Ab3DHJvx (ORCPT ); Mon, 8 Apr 2013 05:51:53 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Johan Hovold , Greg Kroah-Hartman , Luis Henriques Subject: [PATCH 043/102] USB: mct_u232: fix use-after-free in TIOCMIWAIT Date: Mon, 8 Apr 2013 10:49:58 +0100 Message-Id: <1365414657-29191-44-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1365414657-29191-1-git-send-email-luis.henriques@canonical.com> References: <1365414657-29191-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3005 Lines: 87 3.5.7.10 -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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Luis Henriques --- drivers/usb/serial/mct_u232.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c index 66b91d5..5f005cc 100644 --- a/drivers/usb/serial/mct_u232.c +++ b/drivers/usb/serial/mct_u232.c @@ -118,8 +118,6 @@ 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 @@ -399,7 +397,6 @@ static int mct_u232_startup(struct usb_serial *serial) 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); @@ -416,7 +413,6 @@ static int mct_u232_startup(struct usb_serial *serial) return 0; } /* mct_u232_startup */ - static void mct_u232_release(struct usb_serial *serial) { struct mct_u232_private *priv; @@ -616,7 +612,7 @@ static void mct_u232_read_int_callback(struct urb *urb) 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); @@ -827,13 +823,17 @@ static int mct_u232_ioctl(struct tty_struct *tty, 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); -- 1.8.1.2 -- 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/