[3.11.y.z extended stable] Patch "USB: cdc-acm: fix I/O after failed open" 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: cdc-acm: fix I/O after failed open

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 aeff55ff04bcb4d90d83316ad94405d968370c61 Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold at gmail.com>
Date: Mon, 26 May 2014 19:23:44 +0200
Subject: USB: cdc-acm: fix I/O after failed open

commit e4c36076c2a6195ec62c35b03c3fde84d0087dc8 upstream.

Make sure to kill any already submitted read urbs on read-urb submission
failures in open in order to prevent doing I/O for a closed port.

Fixes: 088c64f81284 ("USB: cdc-acm: re-write read processing")
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/class/cdc-acm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index dc5cfa5a1118..83a19ae3c31c 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -494,6 +494,7 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
 {
 	struct acm *acm = container_of(port, struct acm, port);
 	int retval = -ENODEV;
+	int i;

 	dev_dbg(&acm->control->dev, "%s\n", __func__);

@@ -542,6 +543,8 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
 	return 0;

 error_submit_read_urbs:
+	for (i = 0; i < acm->rx_buflimit; i++)
+		usb_kill_urb(acm->read_urbs[i]);
 	acm->ctrlout = 0;
 	acm_set_control(acm, acm->ctrlout);
 error_set_control:
--
1.9.1