[ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.81' (ECDSA) to the list of known hosts. syzkaller login: [ 26.811419] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 26.929542] skbuff: skb_under_panic: text:ffffffff8624fe9f len:48 put:8 head:ffff8880b4901c80 data:ffff8880b4901c7c tail:0x2c end:0xc0 dev:sit1 [ 26.942754] ------------[ cut here ]------------ [ 26.947489] kernel BUG at net/core/skbuff.c:104! [ 26.952268] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 26.957611] Modules linked in: [ 26.960778] CPU: 1 PID: 8006 Comm: syz-executor280 Not tainted 4.14.282-syzkaller #0 [ 26.968634] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.977966] task: ffff8880b351a480 task.stack: ffff888097940000 [ 26.984008] RIP: 0010:skb_panic+0x172/0x174 [ 26.988309] RSP: 0018:ffff888097946e58 EFLAGS: 00010282 [ 26.993646] RAX: 0000000000000083 RBX: ffff88809a87d000 RCX: 0000000000000000 [ 27.000891] RDX: 0000000000000000 RSI: ffffffff878bc600 RDI: ffffed1012f28dc1 [ 27.008132] RBP: ffffffff8855b660 R08: 0000000000000083 R09: 0000000000000000 [ 27.015376] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8624fe9f [ 27.022619] R13: 0000000000000008 R14: ffff8880b35129c0 R15: 00000000000000c0 [ 27.029863] FS: 0000555556079300(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 [ 27.038060] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.043911] CR2: 0000000000000000 CR3: 000000009ae14000 CR4: 00000000003406e0 [ 27.051156] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 27.058397] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 27.065636] Call Trace: [ 27.068202] ? fou_build_udp+0x2f/0x360 [ 27.072153] skb_push.cold+0x24/0x24 [ 27.075839] fou_build_udp+0x2f/0x360 [ 27.079611] gue_build_header+0xd1/0x110 [ 27.083642] ? fou_build_udp+0x360/0x360 [ 27.087674] ? fou_build_udp+0x360/0x360 [ 27.091708] ip_tunnel_xmit+0x50e/0x33e0 [ 27.095746] ? ip_md_tunnel_xmit+0x1060/0x1060 [ 27.100302] ? __lock_acquire+0x5fc/0x3f20 [ 27.104510] ? __lock_acquire+0x5fc/0x3f20 [ 27.108720] ? iptunnel_handle_offloads+0x32e/0x500 [ 27.113713] sit_tunnel_xmit+0x1ab/0x2130 [ 27.117836] ? trace_hardirqs_on+0x10/0x10 [ 27.122055] ? skb_crc32c_csum_help+0x70/0x70 [ 27.126523] ? sit_init_net+0x820/0x820 [ 27.130468] ? inet_addr_type_dev_table+0x2d6/0x480 [ 27.135463] ? netif_skb_features+0x4ed/0x9f0 [ 27.139933] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 27.145357] dev_hard_start_xmit+0x188/0x890 [ 27.149738] __dev_queue_xmit+0x1d7f/0x2480 [ 27.154031] ? trace_hardirqs_on_caller+0x288/0x580 [ 27.159032] ? __neigh_create+0x1022/0x19c0 [ 27.163326] ? netdev_pick_tx+0x2e0/0x2e0 [ 27.167448] ? __neigh_create+0xadb/0x19c0 [ 27.171653] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 27.176648] ? enqueue_to_backlog+0x23f/0xce0 [ 27.181136] ? check_preemption_disabled+0x35/0x240 [ 27.186137] ip_finish_output2+0xba6/0x1340 [ 27.190430] ? do_softirq.part.0+0xcf/0x1b0 [ 27.194721] ? ip_send_check+0xb0/0xb0 [ 27.198579] ? lock_acquire+0x170/0x3f0 [ 27.202526] ip_finish_output+0x37c/0xc50 [ 27.206658] ip_mc_output+0x220/0xcb0 [ 27.210431] ? ip_queue_xmit+0x1b40/0x1b40 [ 27.214646] ? ip_make_skb+0xf2/0x1b0 [ 27.218417] ? ip_forward_options+0x7e0/0x7e0 [ 27.222885] ip_local_out+0x93/0x170 [ 27.226581] ip_send_skb+0x3a/0xc0 [ 27.230102] udp_send_skb+0x601/0xb70 [ 27.233878] udp_sendmsg+0x15a1/0x1c80 [ 27.237740] ? ip_do_fragment+0x1fb0/0x1fb0 [ 27.242035] ? udp_seq_next+0xa0/0xa0 [ 27.245812] ? unwind_get_return_address+0x51/0x90 [ 27.250716] ? entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.256052] ? static_obj+0x50/0x50 [ 27.259663] ? __lock_acquire+0x5fc/0x3f20 [ 27.263870] ? trace_hardirqs_on+0x10/0x10 [ 27.268089] udpv6_sendmsg+0x12ea/0x2560 [ 27.272127] ? trace_hardirqs_on+0x10/0x10 [ 27.276336] ? trace_hardirqs_on+0x10/0x10 [ 27.280543] ? udp_v6_push_pending_frames+0x310/0x310 [ 27.285710] ? reacquire_held_locks+0xb5/0x3f0 [ 27.290279] ? release_sock+0x1b/0x1b0 [ 27.294156] ? ip6_datagram_release_cb+0x270/0x470 [ 27.299154] ? inet_autobind+0x11d/0x180 [ 27.303189] ? lock_downgrade+0x740/0x740 [ 27.307310] ? __local_bh_enable_ip+0xc1/0x170 [ 27.311866] ? trace_hardirqs_on_caller+0x3a8/0x580 [ 27.316856] ? inet_autobind+0x11d/0x180 [ 27.320889] inet_sendmsg+0x11a/0x4e0 [ 27.324660] ? security_socket_sendmsg+0x83/0xb0 [ 27.329387] ? inet_recvmsg+0x4d0/0x4d0 [ 27.333330] sock_sendmsg+0xb5/0x100 [ 27.337017] ___sys_sendmsg+0x326/0x800 [ 27.340963] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 27.345697] ? nlmsg_notify+0x1b0/0x1b0 [ 27.349642] ? kernel_recvmsg+0x210/0x210 [ 27.353764] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 27.359186] ? ___sys_sendmsg+0x423/0x800 [ 27.363304] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 27.368290] ? kfree+0x1f0/0x250 [ 27.371628] ? ___sys_sendmsg+0x428/0x800 [ 27.375748] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 27.380475] ? trace_hardirqs_on+0x10/0x10 [ 27.384680] ? lock_acquire+0x170/0x3f0 [ 27.388623] ? lock_downgrade+0x740/0x740 [ 27.392745] ? __fdget+0x167/0x1f0 [ 27.396261] ? sockfd_lookup_light+0xb2/0x160 [ 27.400729] __sys_sendmmsg+0x129/0x330 [ 27.404673] ? SyS_sendmsg+0x40/0x40 [ 27.408357] ? __might_fault+0x177/0x1b0 [ 27.412389] ? sockfd_lookup_light+0xb2/0x160 [ 27.416855] ? __sys_sendmsg+0xb6/0x120 [ 27.420803] ? SyS_shutdown+0x160/0x160 [ 27.424749] ? up_read+0x17/0x30 [ 27.428085] SyS_sendmmsg+0x2f/0x50 [ 27.431683] ? __sys_sendmmsg+0x330/0x330 [ 27.435804] do_syscall_64+0x1d5/0x640 [ 27.439665] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 27.444828] RIP: 0033:0x7f6d8d543499 [ 27.448522] RSP: 002b:00007ffd28fa4908 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 27.456198] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f6d8d543499 [ 27.463439] RDX: 0000000000000001 RSI: 00000000200017c0 RDI: 0000000000000003 [ 27.470690] RBP: 0000000000000000 R08: 000000008d5b0e40 R09: 000000008d5b0e40 [ 27.477934] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000693b [ 27.485179] R13: 00007ffd28fa4930 R14: 00007ffd28fa4920 R15: 00007ffd28fa4914 [ 27.492423] Code: 8b 4c 24 10 8b 8b 80 00 00 00 41 56 45 89 e8 4c 89 e2 41 57 48 89 ee 48 c7 c7 40 af 55 88 ff 74 24 10 ff 74 24 20 e8 5a 6b e4 ff <0f> 0b e8 ab bf 36 fa 4c 8b 64 24 18 e8 81 61 60 fa 48 c7 c1 60 [ 27.511482] RIP: skb_panic+0x172/0x174 RSP: ffff888097946e58 [ 27.517305] ---[ end trace b47109b5818d3023 ]--- [ 27.522077] Kernel panic - not syncing: Fatal exception in interrupt [ 27.528703] Kernel Offset: disabled [ 27.532306] Rebooting in 86400 seconds..