Index: usb-devel/drivers/usb/core/hcd.c
===================================================================
--- usb-devel.orig/drivers/usb/core/hcd.c
+++ usb-devel/drivers/usb/core/hcd.c
@@ -1563,6 +1563,12 @@ int usb_hcd_submit_urb (struct urb *urb,
 		urb->hcpriv = NULL;
 		INIT_LIST_HEAD(&urb->urb_list);
 		atomic_dec(&urb->use_count);
+		/*
+		 * Order the write of urb->use_count above against the read of
+		 * urb->reject below.  Pairs with the memory barriers in
+		 * usb_kill_urb() and usb_poison_urb().
+		 */
+		smp_mb__after_atomic();
 		atomic_dec(&urb->dev->urbnum);
 		if (atomic_read(&urb->reject))
 			wake_up(&usb_kill_urb_queue);
@@ -1665,6 +1671,13 @@ static void __usb_hcd_giveback_urb(struc
 
 	usb_anchor_resume_wakeups(anchor);
 	atomic_dec(&urb->use_count);
+	/*
+	 * Order the write of urb->use_count above against the read of
+	 * urb->reject below.  Pairs with the memory barriers in
+	 * usb_kill_urb() and usb_poison_urb().
+	 */
+	smp_mb__after_atomic();
+
 	if (unlikely(atomic_read(&urb->reject)))
 		wake_up(&usb_kill_urb_queue);
 	usb_put_urb(urb);
Index: usb-devel/drivers/usb/core/urb.c
===================================================================
--- usb-devel.orig/drivers/usb/core/urb.c
+++ usb-devel/drivers/usb/core/urb.c
@@ -715,6 +715,12 @@ void usb_kill_urb(struct urb *urb)
 	if (!(urb && urb->dev && urb->ep))
 		return;
 	atomic_inc(&urb->reject);
+	/*
+	 * Order the write of urb->reject above against the read of
+	 * urb->use_count below.  Pairs with the barriers in
+	 * __usb_hcd_giveback_urb() and usb_hcd_submit_urb().
+	 */
+	smp_mb__after_atomic();
 
 	usb_hcd_unlink_urb(urb, -ENOENT);
 	wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0);
@@ -756,6 +762,12 @@ void usb_poison_urb(struct urb *urb)
 	if (!urb)
 		return;
 	atomic_inc(&urb->reject);
+	/*
+	 * Order the write of urb->reject above against the read of
+	 * urb->use_count below.  Pairs with the barriers in
+	 * __usb_hcd_giveback_urb() and usb_hcd_submit_urb().
+	 */
+	smp_mb__after_atomic();
 
 	if (!urb->dev || !urb->ep)
 		return;