Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932437AbaGHTPV (ORCPT ); Tue, 8 Jul 2014 15:15:21 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54356 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755767AbaGHTIm (ORCPT ); Tue, 8 Jul 2014 15:08:42 -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, "Johan Hovold" , "Greg Kroah-Hartman" Date: Tue, 08 Jul 2014 20:01:50 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 031/125] USB: usb_wwan: fix write and suspend race In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 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 3.2.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 170fad9e22df0063eba0701adb966786d7a4ec5a upstream. Fix race between write() and suspend() which could lead to writes being dropped (or I/O while suspended) if the device is runtime suspended while a write request is being processed. Specifically, suspend() releases the susp_lock after determining the device is idle but before setting the suspended flag, thus leaving a window where a concurrent write() can submit an urb. Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the option driver") Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- drivers/usb/serial/usb_wwan.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -647,22 +647,19 @@ EXPORT_SYMBOL(usb_wwan_release); int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) { struct usb_wwan_intf_private *intfdata = serial->private; - int b; dbg("%s entered", __func__); + spin_lock_irq(&intfdata->susp_lock); if (PMSG_IS_AUTO(message)) { - spin_lock_irq(&intfdata->susp_lock); - b = intfdata->in_flight; - spin_unlock_irq(&intfdata->susp_lock); - - if (b) + if (intfdata->in_flight) { + spin_unlock_irq(&intfdata->susp_lock); return -EBUSY; + } } - - spin_lock_irq(&intfdata->susp_lock); intfdata->suspended = 1; spin_unlock_irq(&intfdata->susp_lock); + stop_read_write_urbs(serial); return 0; -- 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/