[3.11.y.z extended stable] Patch "USB: usb_wwan: fix urb leak in write error path" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    USB: usb_wwan: fix urb leak in write error path

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 03cb84eb70e68b712057d54b727b5f2858abfe65 Mon Sep 17 00:00:00 2001
From: xiao jin <jin.xiao at intel.com>
Date: Mon, 26 May 2014 19:23:13 +0200
Subject: USB: usb_wwan: fix urb leak in write error path

commit db0904737947d509844e171c9863ecc5b4534005 upstream.

When enable usb serial for modem data, sometimes the tty is blocked
in tty_wait_until_sent because portdata->out_busy always is set and
have no chance to be cleared.

We find a bug in write error path. usb_wwan_write set portdata->out_busy
firstly, then try autopm async with error. No out urb submit and no
usb_wwan_outdat_callback to this write, portdata->out_busy can't be
cleared.

This patch clear portdata->out_busy if usb_wwan_write try autopm async
with error.

Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the
option driver")

Signed-off-by: xiao jin <jin.xiao at intel.com>
Signed-off-by: Zhang, Qi1 <qi1.zhang at intel.com>
Reviewed-by: David Cohen <david.a.cohen at linux.intel.com>
Signed-off-by: Johan Hovold <jhovold at gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/serial/usb_wwan.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c
index 6fa78361be56..7096d0ba1d0f 100644
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -228,8 +228,10 @@ int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
 			usb_pipeendpoint(this_urb->pipe), i);

 		err = usb_autopm_get_interface_async(port->serial->interface);
-		if (err < 0)
+		if (err < 0) {
+			clear_bit(i, &portdata->out_busy);
 			break;
+		}

 		/* send the data */
 		memcpy(this_urb->transfer_buffer, buf, todo);
--
1.9.1