[PATCH] xen: netback: Drop GSO SKBs which do not have csum_blank.

[Ian Campbell <ian.campbell@citrix.com>]

The Linux network stack expects all GSO SKBs to have ip_summed ==
CHECKSUM_PARTIAL (which implies that the frame contains a partial
checksum) and the Xen network ring protocol similarly expects an SKB
which has GSO set to also have NETRX_csum_blank (which also implies a
partial checksum). Therefore drop such frames on receive otherwise
they will trigger the warning in skb_gso_segment.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
---
 drivers/xen/netback/netback.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/xen/netback/netback.c b/drivers/xen/netback/netback.c
index 1e362f7..851721a 100644
--- a/drivers/xen/netback/netback.c
+++ b/drivers/xen/netback/netback.c
@@ -1513,6 +1513,10 @@ static void net_tx_submit(struct xen_netbk *netbk)
 				kfree_skb(skb);
 				continue;
 			}
+		} else if (skb_is_gso(skb)) {
+			DPRINTK("Dropping GSO but not CHECKSUM_PARTIAL skb\n");
+			kfree_skb(skb);
+			continue;
 		}
 
 		if (unlikely(netbk_copy_skb_mode == NETBK_ALWAYS_COPY_SKB) &&
-- 
1.5.6.5