patch "USB: hub: change the locking in hub_activate" added to usb-linus

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    USB: hub: change the locking in hub_activate

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 07d316a22e119fa301fd7dba7f1e1adfd4f72c05 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Fri, 5 Aug 2016 11:51:30 -0400
Subject: USB: hub: change the locking in hub_activate

The locking in hub_activate() is not adequate to provide full mutual
exclusion with hub_quiesce().  The subroutine locks the hub's
usb_interface, but the callers of hub_quiesce() (such as
hub_pre_reset() and hub_event()) hold the lock to the hub's
usb_device.

This patch changes hub_activate() to make it acquire the same lock as
those other routines.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org> #4.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/core/hub.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index bb69d262b6f9..1d5fc32d06d0 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1052,7 +1052,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 
 	/* Continue a partial initialization */
 	if (type == HUB_INIT2 || type == HUB_INIT3) {
-		device_lock(hub->intfdev);
+		device_lock(&hdev->dev);
 
 		/* Was the hub disconnected while we were waiting? */
 		if (hub->disconnected)
@@ -1259,7 +1259,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 			queue_delayed_work(system_power_efficient_wq,
 					&hub->init_work,
 					msecs_to_jiffies(delay));
-			device_unlock(hub->intfdev);
+			device_unlock(&hdev->dev);
 			return;		/* Continues at init3: below */
 		} else {
 			msleep(delay);
@@ -1282,7 +1282,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 		/* Allow autosuspend if it was suppressed */
  disconnected:
 		usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
-		device_unlock(hub->intfdev);
+		device_unlock(&hdev->dev);
 	}
 
 	kref_put(&hub->kref, hub_release);
-- 
2.9.2