This is a note to let you know that I've just added the patch titled USB: usb_wwan: fix write and suspend race to the 3.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-usb_wwan-fix-write-and-suspend-race.patch and it can be found in the queue-3.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 170fad9e22df0063eba0701adb966786d7a4ec5a Mon Sep 17 00:00:00 2001 From: Johan Hovold <jhovold@xxxxxxxxx> Date: Mon, 26 May 2014 19:23:15 +0200 Subject: USB: usb_wwan: fix write and suspend race From: Johan Hovold <jhovold@xxxxxxxxx> 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 <jhovold@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/serial/usb_wwan.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -647,22 +647,20 @@ 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; Patches currently in stable-queue which might be from jhovold@xxxxxxxxx are queue-3.4/usb-usb_wwan-fix-urb-leak-at-shutdown.patch queue-3.4/usb-option-fix-runtime-pm-handling.patch queue-3.4/usb-usb_wwan-fix-write-and-suspend-race.patch queue-3.4/usb-usb_wwan-fix-race-between-write-and-resume.patch queue-3.4/usb-usb_wwan-fix-urb-leak-in-write-error-path.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html