This is a note to let you know that I've just added the patch titled
netvsc: fix incorrect receive checksum offloading
to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netvsc-fix-incorrect-receive-checksum-offloading.patch
and it can be found in the queue-4.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Nov 10 16:43:03 CET 2016
From: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Date: Sun, 23 Oct 2016 21:32:47 -0700
Subject: netvsc: fix incorrect receive checksum offloading
From: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
[ Upstream commit e52fed7177f74382f742c27de2cc5314790aebb6 ]
The Hyper-V netvsc driver was looking at the incorrect status bits
in the checksum info. It was setting the receive checksum unnecessary
flag based on the IP header checksum being correct. The checksum
flag is skb is about TCP and UDP checksum status. Because of this
bug, any packet received with bad TCP checksum would be passed
up the stack and to the application causing data corruption.
The problem is reproducible via netcat and netem.
This had a side effect of not doing receive checksum offload
on IPv6. The driver was also also always doing checksum offload
independent of the checksum setting done via ethtool.
Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/hyperv/netvsc_drv.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -624,15 +624,18 @@ static struct sk_buff *netvsc_alloc_recv
packet->total_data_buflen);
skb->protocol = eth_type_trans(skb, net);
- if (csum_info) {
- /* We only look at the IP checksum here.
- * Should we be dropping the packet if checksum
- * failed? How do we deal with other checksums - TCP/UDP?
- */
- if (csum_info->receive.ip_checksum_succeeded)
+
+ /* skb is already created with CHECKSUM_NONE */
+ skb_checksum_none_assert(skb);
+
+ /*
+ * In Linux, the IP checksum is always checked.
+ * Do L4 checksum offload if enabled and present.
+ */
+ if (csum_info && (net->features & NETIF_F_RXCSUM)) {
+ if (csum_info->receive.tcp_checksum_succeeded ||
+ csum_info->receive.udp_checksum_succeeded)
skb->ip_summed = CHECKSUM_UNNECESSARY;
- else
- skb->ip_summed = CHECKSUM_NONE;
}
if (vlan_tci & VLAN_TAG_PRESENT)
Patches currently in stable-queue which might be from sthemmin@xxxxxxxxxxxxx are
queue-4.8/netvsc-fix-incorrect-receive-checksum-offloading.patch
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