releases/3.16.6/hyperv-fix-a-bug-in-netvsc_send.patch

From foo@baz Sun Oct 12 20:11:55 CEST 2014
From: KY Srinivasan <kys@microsoft.com>
Date: Sun, 5 Oct 2014 10:42:51 -0700
Subject: hyperv: Fix a bug in netvsc_send()

From: KY Srinivasan <kys@microsoft.com>

[ Upstream commit 3a67c9ccad926a168d8b7891537a452018368a5b ]

After the packet is successfully sent, we should not touch the packet
as it may have been freed. This patch is based on the work done by
Long Li <longli@microsoft.com>.

David, please queue this up for stable.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/hyperv/netvsc.c |   15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -708,6 +708,7 @@ int netvsc_send(struct hv_device *device
 	unsigned int section_index = NETVSC_INVALID_INDEX;
 	u32 msg_size = 0;
 	struct sk_buff *skb;
+	u16 q_idx = packet->q_idx;
 
 
 	net_device = get_outbound_net_device(device);
@@ -772,24 +773,24 @@ int netvsc_send(struct hv_device *device
 
 	if (ret == 0) {
 		atomic_inc(&net_device->num_outstanding_sends);
-		atomic_inc(&net_device->queue_sends[packet->q_idx]);
+		atomic_inc(&net_device->queue_sends[q_idx]);
 
 		if (hv_ringbuf_avail_percent(&out_channel->outbound) <
 			RING_AVAIL_PERCENT_LOWATER) {
 			netif_tx_stop_queue(netdev_get_tx_queue(
-					    ndev, packet->q_idx));
+					    ndev, q_idx));
 
 			if (atomic_read(&net_device->
-				queue_sends[packet->q_idx]) < 1)
+				queue_sends[q_idx]) < 1)
 				netif_tx_wake_queue(netdev_get_tx_queue(
-						    ndev, packet->q_idx));
+						    ndev, q_idx));
 		}
 	} else if (ret == -EAGAIN) {
 		netif_tx_stop_queue(netdev_get_tx_queue(
-				    ndev, packet->q_idx));
-		if (atomic_read(&net_device->queue_sends[packet->q_idx]) < 1) {
+				    ndev, q_idx));
+		if (atomic_read(&net_device->queue_sends[q_idx]) < 1) {
 			netif_tx_wake_queue(netdev_get_tx_queue(
-					    ndev, packet->q_idx));
+					    ndev, q_idx));
 			ret = -ENOSPC;
 		}
 	} else {