hyperv: Fix the total_data_buflen in send path

total_data_buflen is used by netvsc_send() to decide if a packet can be put
into send buffer. It should also include the size of RNDIS message before the
Ethernet frame. Otherwise, a messge with total size bigger than send_section_size
may be copied into the send buffer, and cause data corruption.

[Request to include this patch to the Stable branches]

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 9e17d1a91e71..78ec33f5100b 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -550,6 +550,7 @@ do_lso:
 do_send:
         /* Start filling in the page buffers with the rndis hdr */
         rndis_msg->msg_len += rndis_msg_size;
+        packet->total_data_buflen = rndis_msg->msg_len;
         packet->page_buf_cnt = init_page_array(rndis_msg, rndis_msg_size,
                                         skb, &packet->page_buf[0]);