WARNING: CPU: 13 PID: 0 at /build/linux-0XAgc4/linux-4.4.0/net/ipv4/tcp_output.c:1145

[Vinson Lee]

------------[ cut here ]------------
WARNING: CPU: 13 PID: 0 at /build/linux-0XAgc4/linux-4.4.0/net/ipv4/tcp_output.c:1145 tcp_fragment+0x34d/0x370()
Modules linked in: ip6table_filter ipip tunnel4 ip_tunnel cpuid 8021q garp mrp stp llc ip6_tables binfmt_misc xt_comment nf_log_ipv4 nf_log_common xt_LOG xt_limit xt_tcpudp xt_addrtype iptable_filt
 iptable_raw ip_tables x_tables intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel ipmi_ssif aes_x86_64
_helper ablk_helper hpilo cryptd serio_raw sb_edac edac_core ioatdma lpc_ich shpchp 8250_fintek mac_hid acpi_power_meter ipmi_si ipmi_devintf ipmi_msghandler autofs4 raid10 raid456 async_raid6_reco
ync_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear ixgbe dca vxlan ip6_udp_tunnel udp_tunnel ptp ahci pps_core psmouse libahci
 mdio wmi fjes [last unloaded: nf_conntrack]
CPU: 13 PID: 0 Comm: swapper/13 Not tainted 4.4.0-78-generic #99-Ubuntu
 0000000000000286 24b314fc942cf971 ffff88105f3439a8 ffffffff813f8dd3
 0000000000000000 ffffffff81d71d78 ffff88105f3439e0 ffffffff81081302
 ffff88088a1c5000 ffff880cc988f800 000000000000004b 0000000000000000
Call Trace:
 <IRQ> [<ffffffff813f8dd3>] dump_stack+0x63/0x90
 [<ffffffff81081302>] warn_slowpath_common+0x82/0xc0
 [<ffffffff8108144a>] warn_slowpath_null+0x1a/0x20
 [<ffffffff817903ad>] tcp_fragment+0x34d/0x370
 [<ffffffff81785b7f>] tcp_mark_head_lost+0x14f/0x240
 [<ffffffff8178692c>] tcp_update_scoreboard+0x4c/0x70
 [<ffffffff8178c3d2>] tcp_fastretrans_alert+0x6f2/0xaa0
 [<ffffffff8178cbeb>] tcp_ack+0x46b/0x800
 [<ffffffff8178da39>] tcp_rcv_established+0x1d9/0x780
 [<ffffffff8174c232>] ? sk_filter_trim_cap+0x42/0x160
 [<ffffffff81798a05>] tcp_v4_do_rcv+0x145/0x200
 [<ffffffff81799bf2>] tcp_v4_rcv+0x872/0xa20
 [<ffffffffc02290c7>] ? iptable_filter_hook+0x27/0x56 [iptable_filter]
 [<ffffffff8176c172>] ? nf_iterate+0x62/0x80
 [<ffffffff81773504>] ip_local_deliver_finish+0x94/0x1e0
 [<ffffffff8177380f>] ip_local_deliver+0x6f/0xe0
 [<ffffffff81773470>] ? ip_rcv_finish+0x320/0x320
 [<ffffffff817731e2>] ip_rcv_finish+0x92/0x320
 [<ffffffff81773b11>] ip_rcv+0x291/0x3a0
 [<ffffffff81773150>] ? inet_del_offload+0x40/0x40
 [<ffffffff817357a4>] __netif_receive_skb_core+0x704/0xa60
 [<ffffffff8179ec00>] ? tcp4_gro_receive+0x130/0x1d0
 [<ffffffff81735b18>] __netif_receive_skb+0x18/0x60
 [<ffffffff81735b92>] netif_receive_skb_internal+0x32/0xa0
 [<ffffffff81736813>] napi_gro_receive+0xc3/0x120
 [<ffffffffc02b8dfa>] gro_cell_poll+0x5a/0x90 [ip_tunnel]
 [<ffffffff8173605e>] net_rx_action+0x21e/0x360
 [<ffffffff81085de1>] __do_softirq+0x101/0x290
 [<ffffffff810860e3>] irq_exit+0xa3/0xb0
 [<ffffffff81050e13>] smp_call_function_single_interrupt+0x33/0x40
 [<ffffffff81841e62>] call_function_single_interrupt+0x82/0x90
 <EOI> [<ffffffff816d4131>] ? cpuidle_enter_state+0x111/0x2b0
 [<ffffffff816d4307>] cpuidle_enter+0x17/0x20
 [<ffffffff810c4592>] call_cpuidle+0x32/0x60
 [<ffffffff816d42e3>] ? cpuidle_select+0x13/0x20
 [<ffffffff810c4850>] cpu_startup_entry+0x290/0x350
 [<ffffffff810517c4>] start_secondary+0x154/0x190
---[ end trace f0d076c2d7e8bb40 ]---

[Joseph Salisbury (jsalisbury)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1698241

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.

[Vinson Lee (vlee)]

Cannot run apport-collect.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.12 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.12-rc5

[Vinson Lee (vlee)]

This warning does not occur on the Ubuntu 4.8 kernel.

It might be fixed by upstream Linux 4.5 commit d88270eef4b56bd7973841dd1fed387ccfa83709 "tcp: fix tcp_mark_head_lost to check skb len before fragmenting". https://github.com/torvalds/linux/commit/d88270eef4b56bd7973841dd1fed387ccfa83709