I started seeing this too after upgrading to this kernel (from https://ubuntu.com/security/notices/USN-6081-1):
ii linux-image-generic 4.15.0.211.194 ii linux-image-4.15.0-211-generic 4.15.0-211.222
$ cat /proc/version_signature Ubuntu 4.15.0-211.222-generic 4.15.18
From /var/log/syslog: May 27 15:18:43 <hostname> kernel: [22004.663374] ------------[ cut here ]------------ May 27 15:18:43 <hostname> kernel: [22004.663397] WARNING: CPU: 6 PID: 0 at /build/linux-RlFMDZ/linux-4.15.0/net/core/stream.c:212 sk_stream_kill_queues+0xed/0x110 May 27 15:18:43 <hostname> kernel: [22004.663398] Modules linked in: dm_crypt algif_skcipher af_alg nls_iso8859_1 ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 xt_comment ipt_REJECT nf_reject_ipv4 nf_log_ipv4 nf_log_common xt_LOG xt_recent ipt_MASQUERADE nf_nat_masquerade_ipv4 xt_nat intel_rapl ipmi_ssif x86_pkg_temp_thermal intel_powerclamp binfmt_misc kvm_intel kvm irqbypass dcdbas mgag200 iptable_nat ttm nf_nat_ipv4 crct10dif_pclmul xt_limit crc32_pclmul drm_kms_helper xt_tcpudp ghash_clmulni_intel pcbc drm xt_addrtype i2c_algo_bit aesni_intel aes_x86_64 crypto_simd glue_helper cryptd fb_sys_fops syscopyarea intel_cstate sysfillrect intel_rapl_perf sysimgblt lpc_ich shpchp ie31200_edac ipmi_si ipmi_devintf wmi ipmi_msghandler mac_hid nf_conntrack_ipv4 nf_defrag_ipv4 sch_fq_codel xt_conntrack May 27 15:18:43 <hostname> kernel: [22004.663428] ip6table_filter ip6_tables nf_conntrack_netbios_ns nf_conntrack_broadcast nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrack iptable_filter coretemp lp parport ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear raid1 tg3 ahci ptp libahci pps_core May 27 15:18:43 <hostname> kernel: [22004.663444] CPU: 6 PID: 0 Comm: swapper/6 Tainted: G W 4.15.0-211-generic #222-Ubuntu May 27 15:18:43 <hostname> kernel: [22004.663446] Hardware name: Dell Inc. PowerEdge T110 II/0PM2CW, BIOS 2.8.0 06/24/2014 May 27 15:18:43 <hostname> kernel: [22004.663449] RIP: 0010:sk_stream_kill_queues+0xed/0x110 May 27 15:18:43 <hostname> kernel: [22004.663450] RSP: 0018:ffff99813fd83920 EFLAGS: 00010282 May 27 15:18:43 <hostname> kernel: [22004.663452] RAX: 0000000000000024 RBX: ffff997fb1479980 RCX: 0000000000000006 May 27 15:18:43 <hostname> kernel: [22004.663453] RDX: 0000000000000000 RSI: ffff99813fd9b4d8 RDI: ffff99813fd9b4d0 May 27 15:18:43 <hostname> kernel: [22004.663454] RBP: ffff99813fd83930 R08: 0000000000007b7b R09: 0000000000000004 May 27 15:18:43 <hostname> kernel: [22004.663456] R10: ffff99813fd83958 R11: 0000000000000001 R12: ffff997fb1479a48 May 27 15:18:43 <hostname> kernel: [22004.663457] R13: 0000000000000006 R14: 000000000000003c R15: 0000000000000000 May 27 15:18:43 <hostname> kernel: [22004.663459] FS: 0000000000000000(0000) GS:ffff99813fd80000(0000) knlGS:0000000000000000 May 27 15:18:43 <hostname> kernel: [22004.663460] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 May 27 15:18:43 <hostname> kernel: [22004.663461] CR2: 0000563185766000 CR3: 000000027d40a001 CR4: 00000000001606e0 May 27 15:18:43 <hostname> kernel: [22004.663462] Call Trace: May 27 15:18:43 <hostname> kernel: [22004.663465] <IRQ> May 27 15:18:43 <hostname> kernel: [22004.663472] inet_csk_destroy_sock+0x59/0x150 May 27 15:18:43 <hostname> kernel: [22004.663474] tcp_done+0x96/0xa0 May 27 15:18:43 <hostname> kernel: [22004.663476] tcp_time_wait+0x1be/0x280 May 27 15:18:43 <hostname> kernel: [22004.663479] tcp_fin+0x16b/0x180 May 27 15:18:43 <hostname> kernel: [22004.663481] tcp_data_queue+0x594/0xc20 May 27 15:18:43 <hostname> kernel: [22004.663484] tcp_rcv_state_process+0x5dd/0xe70 May 27 15:18:43 <hostname> kernel: [22004.663486] ? skb_clone+0x56/0xc0 May 27 15:18:43 <hostname> kernel: [22004.663490] tcp_v6_do_rcv+0x1ca/0x440 May 27 15:18:43 <hostname> kernel: [22004.663492] ? tcp_v6_do_rcv+0x1ca/0x440 May 27 15:18:43 <hostname> kernel: [22004.663494] tcp_v6_rcv+0x9b6/0xa60 May 27 15:18:43 <hostname> kernel: [22004.663503] ? nf_ct_get_tuple+0x82/0xa0 [nf_conntrack] May 27 15:18:43 <hostname> kernel: [22004.663507] ip6_input_finish+0xcc/0x470 May 27 15:18:43 <hostname> kernel: [22004.663509] ip6_input+0x3f/0xb0 May 27 15:18:43 <hostname> kernel: [22004.663511] ? ipv6_is_mld+0xa0/0xa0 May 27 15:18:43 <hostname> kernel: [22004.663513] ip6_rcv_finish+0xd8/0x120 May 27 15:18:43 <hostname> kernel: [22004.663514] ipv6_rcv+0x347/0x510 May 27 15:18:43 <hostname> kernel: [22004.663516] ? ip6_make_skb+0x200/0x200 May 27 15:18:43 <hostname> kernel: [22004.663520] __netif_receive_skb_core+0x432/0xb80 May 27 15:18:43 <hostname> kernel: [22004.663524] ? tcp6_gro_receive+0x137/0x1a0 May 27 15:18:43 <hostname> kernel: [22004.663527] ? ipv6_gro_receive+0x1a6/0x350 May 27 15:18:43 <hostname> kernel: [22004.663529] __netif_receive_skb+0x18/0x60 May 27 15:18:43 <hostname> kernel: [22004.663531] ? __netif_receive_skb+0x18/0x60 May 27 15:18:43 <hostname> kernel: [22004.663534] netif_receive_skb_internal+0x45/0xe0 May 27 15:18:43 <hostname> kernel: [22004.663537] napi_gro_receive+0xc5/0xf0 May 27 15:18:43 <hostname> kernel: [22004.663542] tg3_poll_work+0x3b2/0xf10 [tg3] May 27 15:18:43 <hostname> kernel: [22004.663548] tg3_poll+0x6b/0x3a0 [tg3] May 27 15:18:43 <hostname> kernel: [22004.663550] net_rx_action+0x140/0x3d0 May 27 15:18:43 <hostname> kernel: [22004.663556] __do_softirq+0xe4/0x2d4 May 27 15:18:43 <hostname> kernel: [22004.663559] irq_exit+0xc5/0xd0 May 27 15:18:43 <hostname> kernel: [22004.663562] do_IRQ+0x86/0xe0 May 27 15:18:43 <hostname> kernel: [22004.663564] common_interrupt+0x90/0x90 May 27 15:18:43 <hostname> kernel: [22004.663565] </IRQ> May 27 15:18:43 <hostname> kernel: [22004.663568] RIP: 0010:cpuidle_enter_state+0xa7/0x2f0 May 27 15:18:43 <hostname> kernel: [22004.663569] RSP: 0018:ffffa697c1947e68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdc May 27 15:18:43 <hostname> kernel: [22004.663571] RAX: ffff99813fda69c0 RBX: 000014035c241b5c RCX: 000000000000001f May 27 15:18:43 <hostname> kernel: [22004.663572] RDX: 000014035c241b5c RSI: ffffffef2d8e461a RDI: 0000000000000000 May 27 15:18:43 <hostname> kernel: [22004.663574] RBP: ffffa697c1947ea8 R08: 0000000000000004 R09: 0000000000026200 May 27 15:18:43 <hostname> kernel: [22004.663575] R10: ffffa697c1947e38 R11: 0000421c1d2b47a9 R12: ffff99813fdb0900 May 27 15:18:43 <hostname> kernel: [22004.663576] R13: 0000000000000004 R14: ffffffffbf7735d8 R15: 0000000000000000 May 27 15:18:43 <hostname> kernel: [22004.663579] ? cpuidle_enter_state+0x97/0x2f0 May 27 15:18:43 <hostname> kernel: [22004.663581] cpuidle_enter+0x17/0x20 May 27 15:18:43 <hostname> kernel: [22004.663584] call_cpuidle+0x23/0x40 May 27 15:18:43 <hostname> kernel: [22004.663587] do_idle+0x18c/0x1f0 May 27 15:18:43 <hostname> kernel: [22004.663590] cpu_startup_entry+0x73/0x80 May 27 15:18:43 <hostname> kernel: [22004.663594] start_secondary+0x1ab/0x200 May 27 15:18:43 <hostname> kernel: [22004.663597] secondary_startup_64+0xa5/0xb0 May 27 15:18:43 <hostname> kernel: [22004.663599] Code: 01 00 00 85 d2 74 df 48 c7 c7 f8 62 2b bf e8 50 49 15 00 0f 0b 8b 83 f8 00 00 00 85 c0 74 d1 48 c7 c7 f8 62 2b bf e8 38 49 15 00 <0f> 0b 5b 41 5c 5d c3 48 c7 c7 f8 62 2b bf e8 25 49 15 00 0f 0b May 27 15:18:43 <hostname> kernel: [22004.663623] ---[ end trace 9048473a62d7540d ]---
I started seeing this too after upgrading to this kernel (from https:/ /ubuntu. com/security/ notices/ USN-6081- 1):
ii linux-image-generic 4.15.0.211.194 4.15.0- 211-generic 4.15.0-211.222
ii linux-image-
$ cat /proc/version_ signature 211.222- generic 4.15.18
Ubuntu 4.15.0-
From /var/log/syslog: linux-RlFMDZ/ linux-4. 15.0/net/ core/stream. c:212 sk_stream_ kill_queues+ 0xed/0x110 masquerade_ ipv4 xt_nat intel_rapl ipmi_ssif x86_pkg_ temp_thermal intel_powerclamp binfmt_misc kvm_intel kvm irqbypass dcdbas mgag200 iptable_nat ttm nf_nat_ipv4 crct10dif_pclmul xt_limit crc32_pclmul drm_kms_helper xt_tcpudp ghash_clmulni_intel pcbc drm xt_addrtype i2c_algo_bit aesni_intel aes_x86_64 crypto_simd glue_helper cryptd fb_sys_fops syscopyarea intel_cstate sysfillrect intel_rapl_perf sysimgblt lpc_ich shpchp ie31200_edac ipmi_si ipmi_devintf wmi ipmi_msghandler mac_hid nf_conntrack_ipv4 nf_defrag_ipv4 sch_fq_codel xt_conntrack netbios_ ns nf_conntrack_ broadcast nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrack iptable_filter coretemp lp parport ip_tables x_tables autofs4 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid0 multipath linear raid1 tg3 ahci ptp libahci pps_core stream_ kill_queues+ 0xed/0x110 d83920 EFLAGS: 00010282 0(0000) GS:ffff99813fd8 0000(0000) knlGS:000000000 0000000 destroy_ sock+0x59/ 0x150 wait+0x1be/ 0x280 queue+0x594/ 0xc20 state_process+ 0x5dd/0xe70 do_rcv+ 0x1ca/0x440 do_rcv+ 0x1ca/0x440 rcv+0x9b6/ 0xa60 tuple+0x82/ 0xa0 [nf_conntrack] finish+ 0xcc/0x470 mld+0xa0/ 0xa0 finish+ 0xd8/0x120 0x347/0x510 skb+0x200/ 0x200 receive_ skb_core+ 0x432/0xb80 receive+ 0x137/0x1a0 receive+ 0x1a6/0x350 receive_ skb+0x18/ 0x60 receive_ skb+0x18/ 0x60 skb_internal+ 0x45/0xe0 receive+ 0xc5/0xf0 work+0x3b2/ 0xf10 [tg3] action+ 0x140/0x3d0 0xe4/0x2d4 interrupt+ 0x90/0x90 enter_state+ 0xa7/0x2f0 947e68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdc enter_state+ 0x97/0x2f0 enter+0x17/ 0x20 0x23/0x40 entry+0x73/ 0x80 +0x1ab/ 0x200 startup_ 64+0xa5/ 0xb0
May 27 15:18:43 <hostname> kernel: [22004.663374] ------------[ cut here ]------------
May 27 15:18:43 <hostname> kernel: [22004.663397] WARNING: CPU: 6 PID: 0 at /build/
May 27 15:18:43 <hostname> kernel: [22004.663398] Modules linked in: dm_crypt algif_skcipher af_alg nls_iso8859_1 ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 xt_comment ipt_REJECT nf_reject_ipv4 nf_log_ipv4 nf_log_common xt_LOG xt_recent ipt_MASQUERADE nf_nat_
May 27 15:18:43 <hostname> kernel: [22004.663428] ip6table_filter ip6_tables nf_conntrack_
May 27 15:18:43 <hostname> kernel: [22004.663444] CPU: 6 PID: 0 Comm: swapper/6 Tainted: G W 4.15.0-211-generic #222-Ubuntu
May 27 15:18:43 <hostname> kernel: [22004.663446] Hardware name: Dell Inc. PowerEdge T110 II/0PM2CW, BIOS 2.8.0 06/24/2014
May 27 15:18:43 <hostname> kernel: [22004.663449] RIP: 0010:sk_
May 27 15:18:43 <hostname> kernel: [22004.663450] RSP: 0018:ffff99813f
May 27 15:18:43 <hostname> kernel: [22004.663452] RAX: 0000000000000024 RBX: ffff997fb1479980 RCX: 0000000000000006
May 27 15:18:43 <hostname> kernel: [22004.663453] RDX: 0000000000000000 RSI: ffff99813fd9b4d8 RDI: ffff99813fd9b4d0
May 27 15:18:43 <hostname> kernel: [22004.663454] RBP: ffff99813fd83930 R08: 0000000000007b7b R09: 0000000000000004
May 27 15:18:43 <hostname> kernel: [22004.663456] R10: ffff99813fd83958 R11: 0000000000000001 R12: ffff997fb1479a48
May 27 15:18:43 <hostname> kernel: [22004.663457] R13: 0000000000000006 R14: 000000000000003c R15: 0000000000000000
May 27 15:18:43 <hostname> kernel: [22004.663459] FS: 000000000000000
May 27 15:18:43 <hostname> kernel: [22004.663460] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
May 27 15:18:43 <hostname> kernel: [22004.663461] CR2: 0000563185766000 CR3: 000000027d40a001 CR4: 00000000001606e0
May 27 15:18:43 <hostname> kernel: [22004.663462] Call Trace:
May 27 15:18:43 <hostname> kernel: [22004.663465] <IRQ>
May 27 15:18:43 <hostname> kernel: [22004.663472] inet_csk_
May 27 15:18:43 <hostname> kernel: [22004.663474] tcp_done+0x96/0xa0
May 27 15:18:43 <hostname> kernel: [22004.663476] tcp_time_
May 27 15:18:43 <hostname> kernel: [22004.663479] tcp_fin+0x16b/0x180
May 27 15:18:43 <hostname> kernel: [22004.663481] tcp_data_
May 27 15:18:43 <hostname> kernel: [22004.663484] tcp_rcv_
May 27 15:18:43 <hostname> kernel: [22004.663486] ? skb_clone+0x56/0xc0
May 27 15:18:43 <hostname> kernel: [22004.663490] tcp_v6_
May 27 15:18:43 <hostname> kernel: [22004.663492] ? tcp_v6_
May 27 15:18:43 <hostname> kernel: [22004.663494] tcp_v6_
May 27 15:18:43 <hostname> kernel: [22004.663503] ? nf_ct_get_
May 27 15:18:43 <hostname> kernel: [22004.663507] ip6_input_
May 27 15:18:43 <hostname> kernel: [22004.663509] ip6_input+0x3f/0xb0
May 27 15:18:43 <hostname> kernel: [22004.663511] ? ipv6_is_
May 27 15:18:43 <hostname> kernel: [22004.663513] ip6_rcv_
May 27 15:18:43 <hostname> kernel: [22004.663514] ipv6_rcv+
May 27 15:18:43 <hostname> kernel: [22004.663516] ? ip6_make_
May 27 15:18:43 <hostname> kernel: [22004.663520] __netif_
May 27 15:18:43 <hostname> kernel: [22004.663524] ? tcp6_gro_
May 27 15:18:43 <hostname> kernel: [22004.663527] ? ipv6_gro_
May 27 15:18:43 <hostname> kernel: [22004.663529] __netif_
May 27 15:18:43 <hostname> kernel: [22004.663531] ? __netif_
May 27 15:18:43 <hostname> kernel: [22004.663534] netif_receive_
May 27 15:18:43 <hostname> kernel: [22004.663537] napi_gro_
May 27 15:18:43 <hostname> kernel: [22004.663542] tg3_poll_
May 27 15:18:43 <hostname> kernel: [22004.663548] tg3_poll+0x6b/0x3a0 [tg3]
May 27 15:18:43 <hostname> kernel: [22004.663550] net_rx_
May 27 15:18:43 <hostname> kernel: [22004.663556] __do_softirq+
May 27 15:18:43 <hostname> kernel: [22004.663559] irq_exit+0xc5/0xd0
May 27 15:18:43 <hostname> kernel: [22004.663562] do_IRQ+0x86/0xe0
May 27 15:18:43 <hostname> kernel: [22004.663564] common_
May 27 15:18:43 <hostname> kernel: [22004.663565] </IRQ>
May 27 15:18:43 <hostname> kernel: [22004.663568] RIP: 0010:cpuidle_
May 27 15:18:43 <hostname> kernel: [22004.663569] RSP: 0018:ffffa697c1
May 27 15:18:43 <hostname> kernel: [22004.663571] RAX: ffff99813fda69c0 RBX: 000014035c241b5c RCX: 000000000000001f
May 27 15:18:43 <hostname> kernel: [22004.663572] RDX: 000014035c241b5c RSI: ffffffef2d8e461a RDI: 0000000000000000
May 27 15:18:43 <hostname> kernel: [22004.663574] RBP: ffffa697c1947ea8 R08: 0000000000000004 R09: 0000000000026200
May 27 15:18:43 <hostname> kernel: [22004.663575] R10: ffffa697c1947e38 R11: 0000421c1d2b47a9 R12: ffff99813fdb0900
May 27 15:18:43 <hostname> kernel: [22004.663576] R13: 0000000000000004 R14: ffffffffbf7735d8 R15: 0000000000000000
May 27 15:18:43 <hostname> kernel: [22004.663579] ? cpuidle_
May 27 15:18:43 <hostname> kernel: [22004.663581] cpuidle_
May 27 15:18:43 <hostname> kernel: [22004.663584] call_cpuidle+
May 27 15:18:43 <hostname> kernel: [22004.663587] do_idle+0x18c/0x1f0
May 27 15:18:43 <hostname> kernel: [22004.663590] cpu_startup_
May 27 15:18:43 <hostname> kernel: [22004.663594] start_secondary
May 27 15:18:43 <hostname> kernel: [22004.663597] secondary_
May 27 15:18:43 <hostname> kernel: [22004.663599] Code: 01 00 00 85 d2 74 df 48 c7 c7 f8 62 2b bf e8 50 49 15 00 0f 0b 8b 83 f8 00 00 00 85 c0 74 d1 48 c7 c7 f8 62 2b bf e8 38 49 15 00 <0f> 0b 5b 41 5c 5d c3 48 c7 c7 f8 62 2b bf e8 25 49 15 00 0f 0b
May 27 15:18:43 <hostname> kernel: [22004.663623] ---[ end trace 9048473a62d7540d ]---