This is a note to let you know that I've just added the patch titled mactap: Fix checksum errors for non-gso packets in to the 3.14-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: mactap-fix-checksum-errors-for-non-gso-packets-in.patch and it can be found in the queue-3.14 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 Wed May 28 21:03:54 PDT 2014 From: Vlad Yasevich <vyasevic@xxxxxxxxxx> Date: Tue, 29 Apr 2014 10:09:50 -0400 Subject: mactap: Fix checksum errors for non-gso packets in bridge mode From: Vlad Yasevich <vyasevic@xxxxxxxxxx> [ Upstream commit cbdb04279ccaefcc702c8757757eea8ed76e50cf ] The following is a problematic configuration: VM1: virtio-net device connected to macvtap0@eth0 VM2: e1000 device connect to macvtap1@eth0 The problem is is that virtio-net supports checksum offloading and thus sends the packets to the host with CHECKSUM_PARTIAL set. On the other hand, e1000 does not support any acceleration. For small TCP packets (and this includes the 3-way handshake), e1000 ends up receiving packets that only have a partial checksum set. This causes TCP to fail checksum validation and to drop packets. As a result tcp connections can not be established. Commit 3e4f8b787370978733ca6cae452720a4f0c296b8 macvtap: Perform GSO on forwarding path. fixes this issue for large packets wthat will end up undergoing GSO. This commit adds a check for the non-GSO case and attempts to compute the checksum for partially checksummed packets in the non-GSO case. CC: Daniel Lezcano <daniel.lezcano@xxxxxxx> CC: Patrick McHardy <kaber@xxxxxxxxx> CC: Andrian Nord <nightnord@xxxxxxxxx> CC: Eric Dumazet <eric.dumazet@xxxxxxxxx> CC: Michael S. Tsirkin <mst@xxxxxxxxxx> CC: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: Vlad Yasevich <vyasevic@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/macvtap.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -322,6 +322,15 @@ static rx_handler_result_t macvtap_handl segs = nskb; } } else { + /* If we receive a partial checksum and the tap side + * doesn't support checksum offload, compute the checksum. + * Note: it doesn't matter which checksum feature to + * check, we either support them all or none. + */ + if (skb->ip_summed == CHECKSUM_PARTIAL && + !(features & NETIF_F_ALL_CSUM) && + skb_checksum_help(skb)) + goto drop; skb_queue_tail(&q->sk.sk_receive_queue, skb); } Patches currently in stable-queue which might be from vyasevic@xxxxxxxxxx are queue-3.14/net-start-with-correct-mac_len-in-skb_network_protocol.patch queue-3.14/net-find-the-nesting-level-of-a-given-device-by-type.patch queue-3.14/mactap-fix-checksum-errors-for-non-gso-packets-in.patch queue-3.14/net-allow-for-more-then-a-single-subclass-for.patch queue-3.14/macvlan-fix-lockdep-warnings-with-stacked-macvlan.patch queue-3.14/revert-macvlan-fix-checksums-error-when-we-are-in.patch queue-3.14/net-sctp-cache-auth_enable-per-endpoint.patch queue-3.14/net-sctp-test-if-association-is-dead-in-sctp_wake_up_waiters.patch queue-3.14/net-sctp-wake-up-all-assocs-if-sndbuf-policy-is-per-socket.patch queue-3.14/vlan-fix-lockdep-warning-with-stacked-vlan-devices.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html