[PATCH net] hyperv: Fix the total_data_buflen in send path

[PATCH net] hyperv: Fix the total_data_buflen in send path

[Haiyang Zhang]

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>
---
 drivers/net/hyperv/netvsc_drv.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 9e17d1a..78ec33f 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]);
 
-- 
1.7.1

Re: [PATCH net] hyperv: Fix the total_data_buflen in send path

[David Miller]

From: Haiyang Zhang <haiyangz@microsoft.com>
Date: Wed, 22 Oct 2014 13:47:18 -0700

> 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>

Applied and queued up for -stable, thanks.