This bug is missing log files that will aid in diagnosing the problem. >From a terminal window please run:
apport-collect 1409123 and then change the status of the bug to 'Confirmed'. If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'. This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1409123 Title: "hw csum failure" in encapsulated network topolgies Status in linux package in Ubuntu: Triaged Bug description: Virtualized network topologies that utilize encapsulation (e.g., VXLAN) and bridging may experience kernel errors of the format: [ 4297.761899] eth0: hw csum failure [ 4297.765210] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G OE 3.18.0-rc4 -nn+ #22 [ 4297.765212] Hardware name: LENOVO 0829F3U/To be filled by O.E.M., BIOS 90KT15 AUS 07/21/2010 [ 4297.765216] 0000000000000000 ffff88013fc03ba8 ffffffff8172f026 0000000000000 001 [ 4297.765219] ffff88013870e000 ffff88013fc03bc8 ffffffff8162ba52 ffffffff8161c 1a0 [ 4297.765221] ffff8800afdf1000 ffff88013fc03c08 ffffffff8162325c ffff88013870e 000 [ 4297.765223] Call Trace: [ 4297.765224] <IRQ> [<ffffffff8172f026>] dump_stack+0x46/0x58 [ 4297.765235] [<ffffffff8162ba52>] netdev_rx_csum_fault+0x42/0x50 [ 4297.765238] [<ffffffff8161c1a0>] ? skb_push+0x40/0x40 [ 4297.765240] [<ffffffff8162325c>] __skb_checksum_complete+0xbc/0xd0 [ 4297.765243] [<ffffffff8168c602>] tcp_v4_rcv+0x2e2/0x950 [ 4297.765246] [<ffffffff81666ca0>] ? ip_rcv_finish+0x360/0x360 [ 4297.765248] [<ffffffff81660224>] ? nf_hook_slow+0x74/0x130 [ 4297.765250] [<ffffffff81666ca0>] ? ip_rcv_finish+0x360/0x360 [ 4297.765253] [<ffffffff81666d4c>] ip_local_deliver_finish+0xac/0x220 [ 4297.765255] [<ffffffff81667058>] ip_local_deliver+0x48/0x80 [ 4297.765257] [<ffffffff816669c1>] ip_rcv_finish+0x81/0x360 [ 4297.765259] [<ffffffff81667332>] ip_rcv+0x2a2/0x3f0 [ 4297.765261] [<ffffffff8162e932>] __netif_receive_skb_core+0x562/0x7a0 [ 4297.765263] [<ffffffff8162eb88>] __netif_receive_skb+0x18/0x60 [ 4297.765265] [<ffffffff8162f8f6>] process_backlog+0xa6/0x150 The backtrace may vary, stacks descending into conntrack have also been observed: Call Trace: <IRQ> [<ffffffff8171a324>] dump_stack+0x45/0x56 [<ffffffff8161bfba>] netdev_rx_csum_fault+0x3a/0x40 [<ffffffff81614782>] __skb_checksum_complete_head+0x62/0x70 [<ffffffff816147a1>] __skb_checksum_complete+0x11/0x20 [<ffffffff816a3eac>] nf_ip_checksum+0xcc/0x100 [<ffffffffa04df33b>] udp_error+0xdb/0x1f0 [nf_conntrack] [<ffffffffa04d926e>] nf_conntrack_in+0xee/0xb40 [nf_conntrack] [<ffffffffa0307653>] ? do_execute_actions+0x2e3/0xab0 [openvswitch] [<ffffffffa0307e4b>] ? ovs_execute_actions+0x2b/0x30 [openvswitch] [<ffffffff81654540>] ? inet_del_offload+0x40/0x40 [<ffffffffa03b52e2>] ipv4_conntrack_in+0x22/0x30 [nf_conntrack_ipv4] [<ffffffff8164e0aa>] nf_iterate+0x9a/0xb0 [<ffffffff81654540>] ? inet_del_offload+0x40/0x40 [<ffffffff8164e134>] nf_hook_slow+0x74/0x130 [<ffffffff81654540>] ? inet_del_offload+0x40/0x40 [<ffffffff81654f68>] ip_rcv+0x2f8/0x3d0 The root cause of this is twofold: First, the kernel handling of forwarded packets that have been encapsulated (e.g., from VXLAN) for devices that support CHECKSUM_COMPLETE checksum offload fails to update the running checksum when decapsulating the packet. Second, for the enic device itself, the hardware is not correctly computing the checksum for some cases. Both of these issues are patched in mainline: commit 17e96834fd35997ca7cdfbf15413bcd5a36ad448 Author: Govindarajulu Varadarajan <_gov...@gmx.com> Date: Thu Dec 18 15:58:42 2014 +0530 enic: fix rx skb checksum commit 2c26d34bbcc0b3f30385d5587aa232289e2eed8e Author: Jay Vosburgh <jay.vosbu...@canonical.com> Date: Fri Dec 19 15:32:00 2014 -0800 net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1409123/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp