From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935652Ab3DHJvw (ORCPT ); Mon, 8 Apr 2013 05:51:52 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42764 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935594Ab3DHJvr (ORCPT ); Mon, 8 Apr 2013 05:51:47 -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 038/102] USB: cypress_m8: fix use-after-free in TIOCMIWAIT Date: Mon, 8 Apr 2013 10:49:53 +0100 Message-Id: <1365414657-29191-39-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 3.5.7.10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 356050d8b1e526db093e9d2c78daf49d6bf418e3 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. Also remove bogus test for private data pointer being NULL as it is never assigned in the loop. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman Signed-off-by: Luis Henriques --- drivers/usb/serial/cypress_m8.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c index b78c34e..dec5b2f 100644 --- a/drivers/usb/serial/cypress_m8.c +++ b/drivers/usb/serial/cypress_m8.c @@ -116,7 +116,6 @@ struct cypress_private { int baud_rate; /* stores current baud rate in integer form */ int isthrottled; /* if throttled, discard reads */ - wait_queue_head_t delta_msr_wait; /* used for TIOCMIWAIT */ char prev_status, diff_status; /* used for TIOCMIWAIT */ /* we pass a pointer to this as the argument sent to cypress_set_termios old_termios */ @@ -452,7 +451,6 @@ static int generic_startup(struct usb_serial *serial) kfree(priv); return -ENOMEM; } - init_waitqueue_head(&priv->delta_msr_wait); usb_reset_configuration(serial->dev); @@ -872,12 +870,16 @@ static int cypress_ioctl(struct tty_struct *tty, switch (cmd) { /* This code comes from drivers/char/serial.c and ftdi_sio.c */ case TIOCMIWAIT: - while (priv != NULL) { - interruptible_sleep_on(&priv->delta_msr_wait); + for (;;) { + interruptible_sleep_on(&port->delta_msr_wait); /* see if a signal did it */ if (signal_pending(current)) return -ERESTARTSYS; - else { + + if (port->serial->disconnected) + return -EIO; + + { char diff = priv->diff_status; if (diff == 0) return -EIO; /* no change => error */ @@ -1193,7 +1195,7 @@ static void cypress_read_int_callback(struct urb *urb) if (priv->current_status != priv->prev_status) { priv->diff_status |= priv->current_status ^ priv->prev_status; - wake_up_interruptible(&priv->delta_msr_wait); + wake_up_interruptible(&port->delta_msr_wait); priv->prev_status = priv->current_status; } spin_unlock_irqrestore(&priv->lock, flags); -- 1.8.1.2