Sep 11 01:39:02 inet777 kernel: [263528.341043] ------------[ cut here ]------------ Sep 11 01:39:02 inet777 kernel: [263528.341066] WARNING: CPU: 2 PID: 0 at /build/linux-ELRFVQ/linux-3.16.7-ckt11/net/ipv4/tcp_output.c:1085 tcp_fragment+0x2b1/0x2c0() Sep 11 01:39:02 inet777 kernel: [263528.341071] Modules linked in: xt_nat iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt _conntrack nf_conntrack ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables tcp_htcp loop x86_pkg_temp_thermal intel_powerclamp intel_rap l coretemp kvm_intel iTCO_wdt kvm ppdev iTCO_vendor_support i915 evdev crc32_pclmul ghash_clmulni_intel drm_kms_helper drm shpchp aesni_inte l psmouse serio_raw pcspkr aes_x86_64 lrw gf128mul glue_helper ablk_helper tpm_infineon cryptd tpm_tis i2c_i801 battery tpm i2c_algo_bit par port_pc parport i2c_core lpc_ich mfd_core mei_me mei video button processor ext4 crc16 mbcache jbd2 raid1 md_mod sg sd_mod crc_t10dif crct10 dif_generic ata_generic ata_piix crct10dif_pclmul crct10dif_common crc32c_intel libata scsi_mod 8139too r8169 8139cp mii fan thermal thermal _sys Sep 11 01:39:02 inet777 kernel: [263528.341128] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 3.16.0-4-amd64 #1 Debian 3.16.7-ckt11-1+deb8u3 Sep 11 01:39:02 inet777 kernel: [263528.341130] Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./B75M-D3H, BIOS F13 02/27 /2013 Sep 11 01:39:02 inet777 kernel: [263528.341132] 0000000000000009 ffffffff8150b3a5 0000000000000000 ffffffff81067767 Sep 11 01:39:02 inet777 kernel: [263528.341135] ffff8802139a9200 ffff8801e47587c0 0000000000000001 0000000000000200 Sep 11 01:39:02 inet777 kernel: [263528.341138] 00000000c1c44e2b ffffffff8146edd1 ffff8802139a9200 ffff8801e47587c0 Sep 11 01:39:02 inet777 kernel: [263528.341142] Call Trace: Sep 11 01:39:02 inet777 kernel: [263528.341143] <IRQ> [<ffffffff8150b3a5>] ? dump_stack+0x41/0x51 Sep 11 01:39:02 inet777 kernel: [263528.341155] [<ffffffff81067767>] ? warn_slowpath_common+0x77/0x90 Sep 11 01:39:02 inet777 kernel: [263528.341159] [<ffffffff8146edd1>] ? tcp_fragment+0x2b1/0x2c0 Sep 11 01:39:02 inet777 kernel: [263528.341163] [<ffffffff8146583e>] ? tcp_mark_head_lost+0x19e/0x260 Sep 11 01:39:02 inet777 kernel: [263528.341167] [<ffffffff8146a9a6>] ? tcp_fastretrans_alert+0x626/0xac0 Sep 11 01:39:02 inet777 kernel: [263528.341171] [<ffffffff8146b7b5>] ? tcp_ack+0x875/0x11d0 Sep 11 01:39:02 inet777 kernel: [263528.341175] [<ffffffff8146d018>] ? tcp_rcv_state_process+0x298/0xf40 Sep 11 01:39:02 inet777 kernel: [263528.341179] [<ffffffff8147650e>] ? tcp_v4_do_rcv+0x29e/0x4c0 Sep 11 01:39:02 inet777 kernel: [263528.341185] [<ffffffffa04c4ba4>] ? ipv4_confirm+0x74/0xf0 [nf_conntrack_ipv4] Sep 11 01:39:02 inet777 kernel: [263528.341188] [<ffffffff814781d6>] ? tcp_v4_rcv+0x696/0x7a0 Sep 11 01:39:02 inet777 kernel: [263528.341192] [<ffffffff8144d776>] ? nf_hook_slow+0x76/0x130 Sep 11 01:39:02 inet777 kernel: [263528.341194] [<ffffffff81453be0>] ? ip_rcv_finish+0x350/0x350 Sep 11 01:39:02 inet777 kernel: [263528.341197] [<ffffffff81453c7e>] ? ip_local_deliver_finish+0x9e/0x200 Sep 11 01:39:02 inet777 kernel: [263528.341201] [<ffffffff8141cd23>] ? __netif_receive_skb_core+0x533/0x750 Sep 11 01:39:02 inet777 kernel: [263528.341206] [<ffffffff8101b555>] ? read_tsc+0x5/0x20 Sep 11 01:39:02 inet777 kernel: [263528.341209] [<ffffffff8141cfbf>] ? netif_receive_skb_internal+0x1f/0x90 Sep 11 01:39:02 inet777 kernel: [263528.341215] [<ffffffffa000ebf1>] ? rtl8139_poll+0x1c1/0x600 [8139too] Sep 11 01:39:02 inet777 kernel: [263528.341218] [<ffffffff8141d350>] ? net_rx_action+0x140/0x240 Sep 11 01:39:02 inet777 kernel: [263528.341222] [<ffffffff8106c611>] ? __do_softirq+0xf1/0x290 Sep 11 01:39:02 inet777 kernel: [263528.341225] [<ffffffff8106c9e5>] ? irq_exit+0x95/0xa0 Sep 11 01:39:02 inet777 kernel: [263528.341228] [<ffffffff815143a2>] ? do_IRQ+0x52/0xe0 Sep 11 01:39:02 inet777 kernel: [263528.341232] [<ffffffff815121ed>] ? common_interrupt+0x6d/0x6d Sep 11 01:39:02 inet777 kernel: [263528.341234] <EOI> [<ffffffff8108ad0d>] ? __hrtimer_start_range_ns+0x1cd/0x390 Sep 11 01:39:02 inet777 kernel: [263528.341242] [<ffffffff813ddf72>] ? cpuidle_enter_state+0x52/0xc0 Sep 11 01:39:02 inet777 kernel: [263528.341246] [<ffffffff813ddf68>] ? cpuidle_enter_state+0x48/0xc0 Sep 11 01:39:02 inet777 kernel: [263528.341251] [<ffffffff810a7f78>] ? cpu_startup_entry+0x2f8/0x400 Sep 11 01:39:02 inet777 kernel: [263528.341254] [<ffffffff81042daf>] ? start_secondary+0x20f/0x2d0 Sep 11 01:39:02 inet777 kernel: [263528.341257] ---[ end trace 17942609c932f105 ]--- Possible it with network activity I use iptables iptables -V iptables v1.4.21 and config: /sbin/ifconfig eth0 txqueuelen 5000