INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-net-kasan-gce-4,10.128.15.200' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 231.670647] random: crng init done executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 244.647283] refcount_t: underflow; use-after-free. [ 244.652335] ------------[ cut here ]------------ [ 244.657570] WARNING: CPU: 0 PID: 14069 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 244.666348] Kernel panic - not syncing: panic_on_warn set ... [ 244.666348] [ 244.673689] CPU: 0 PID: 14069 Comm: syzkaller451577 Not tainted 4.13.0-rc6+ #25 [ 244.681103] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 244.690428] Call Trace: [ 244.692984] dump_stack+0x194/0x257 [ 244.696580] ? arch_local_irq_restore+0x53/0x53 [ 244.701226] panic+0x1e4/0x417 [ 244.704386] ? __warn+0x1d9/0x1d9 [ 244.707804] ? show_regs_print_info+0x65/0x65 [ 244.712281] ? refcount_sub_and_test+0x167/0x1b0 [ 244.717004] __warn+0x1c4/0x1d9 [ 244.720255] ? refcount_sub_and_test+0x167/0x1b0 [ 244.724983] report_bug+0x211/0x2d0 [ 244.728585] fixup_bug+0x40/0x90 [ 244.731928] do_trap+0x260/0x390 [ 244.735274] do_error_trap+0x120/0x390 [ 244.739135] ? do_trap+0x390/0x390 [ 244.742642] ? refcount_sub_and_test+0x167/0x1b0 [ 244.747361] ? vprintk_emit+0x3ea/0x590 [ 244.751318] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 244.756149] do_invalid_op+0x1b/0x20 [ 244.759831] invalid_op+0x1e/0x30 [ 244.763252] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 244.768578] RSP: 0018:ffff8801c1fde330 EFLAGS: 00010286 [ 244.773907] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 244.781145] RDX: 0000000000000026 RSI: 1ffff100383fbc26 RDI: ffffed00383fbc5a [ 244.788384] RBP: ffff8801c1fde3c0 R08: 0000000000000001 R09: 0000000000000000 [ 244.795622] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff100383fbc67 [ 244.802857] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801c19512fc [ 244.810120] ? refcount_inc+0x50/0x50 [ 244.814071] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 244.818794] ? sctp_association_free+0x2d0/0x930 [ 244.823517] ? sctp_do_sm+0x28e7/0x6dd0 [ 244.827464] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 244.832185] ? sctp_close+0x3c6/0x980 [ 244.835954] ? inet_release+0xed/0x1c0 [ 244.839817] sctp_wfree+0x183/0x620 [ 244.843430] ? __sctp_write_space+0x910/0x910 [ 244.847910] skb_release_head_state+0x124/0x200 [ 244.852549] skb_release_all+0x15/0x60 [ 244.856403] consume_skb+0x153/0x490 [ 244.860084] ? sctp_chunk_put+0x99/0x420 [ 244.864111] ? alloc_skb_with_frags+0x710/0x710 [ 244.868747] ? sctp_chunk_hold+0x20/0x20 [ 244.872777] ? refcount_sub_and_test+0x115/0x1b0 [ 244.877500] ? refcount_inc+0x50/0x50 [ 244.881267] ? mark_held_locks+0xaf/0x100 [ 244.885385] ? sctp_datamsg_put+0x456/0x560 [ 244.889680] sctp_chunk_put+0x29c/0x420 [ 244.893624] ? sctp_chunk_hold+0x20/0x20 [ 244.897652] ? sctp_transport_dst_confirm+0x50/0x50 [ 244.902634] ? __lock_acquire+0x6ef/0x3dc0 [ 244.906841] ? print_usage_bug+0x480/0x480 [ 244.911040] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 244.916034] sctp_chunk_free+0x53/0x60 [ 244.919890] __sctp_outq_teardown+0xc7d/0x15a0 [ 244.924454] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 244.929356] ? print_usage_bug+0x480/0x480 [ 244.933563] ? check_noncircular+0x20/0x20 [ 244.937767] ? print_usage_bug+0x480/0x480 [ 244.941968] ? print_usage_bug+0x480/0x480 [ 244.946169] ? print_usage_bug+0x480/0x480 [ 244.950372] ? __lock_acquire+0x6ef/0x3dc0 [ 244.954577] ? print_usage_bug+0x480/0x480 [ 244.958777] ? check_noncircular+0x20/0x20 [ 244.962985] ? print_usage_bug+0x480/0x480 [ 244.967191] ? check_noncircular+0x20/0x20 [ 244.971392] ? print_usage_bug+0x480/0x480 [ 244.975601] ? check_noncircular+0x20/0x20 [ 244.979804] ? find_held_lock+0x35/0x1d0 [ 244.983837] ? lock_acquire+0x1d5/0x580 [ 244.987776] ? lock_acquire+0x1d5/0x580 [ 244.991729] ? lock_timer_base+0x1a3/0x2b0 [ 244.995947] ? find_held_lock+0x35/0x1d0 [ 244.999987] ? sock_def_wakeup+0x1f9/0x350 [ 245.004191] ? lock_downgrade+0x990/0x990 [ 245.008324] ? lock_release+0xa40/0xa40 [ 245.012281] sctp_outq_free+0x15/0x20 [ 245.016050] sctp_association_free+0x2d0/0x930 [ 245.020605] ? sctp_asconf_queue_teardown+0x700/0x700 [ 245.025761] ? sock_def_wakeup+0x222/0x350 [ 245.029964] ? sk_dst_check+0x560/0x560 [ 245.033908] ? sctp_association_put+0x74/0x2f0 [ 245.038460] ? sctp_association_hold+0x20/0x20 [ 245.043020] ? unwind_get_return_address+0x61/0xa0 [ 245.047928] ? print_usage_bug+0x480/0x480 [ 245.052129] ? sctp_sm_lookup_event+0x95/0x3c0 [ 245.056681] sctp_do_sm+0x28e7/0x6dd0 [ 245.060463] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 245.066496] ? get_signal+0x7e8/0x17e0 [ 245.070361] ? print_usage_bug+0x480/0x480 [ 245.074567] ? check_noncircular+0x20/0x20 [ 245.078772] ? print_usage_bug+0x480/0x480 [ 245.082985] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 245.088151] ? check_noncircular+0x20/0x20 [ 245.092371] ? find_held_lock+0x35/0x1d0 [ 245.096407] ? skb_dequeue+0x12a/0x180 [ 245.100269] ? lock_downgrade+0x990/0x990 [ 245.104391] ? do_raw_spin_trylock+0x190/0x190 [ 245.108948] ? mark_held_locks+0xaf/0x100 [ 245.113076] ? trace_hardirqs_on+0xd/0x10 [ 245.117196] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 245.121752] sctp_close+0x3c6/0x980 [ 245.125356] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 245.130603] ? __save_stack_trace+0x7e/0xd0 [ 245.134902] ? depot_save_stack+0x12c/0x490 [ 245.139203] ? locks_remove_file+0x414/0x560 [ 245.143585] ? fcntl_setlk+0x10c0/0x10c0 [ 245.147613] ? free_fs_struct+0x4f/0x60 [ 245.151559] ? __fsnotify_parent+0xb4/0x3a0 [ 245.155853] ? ip_mc_drop_socket+0x1ce/0x230 [ 245.160237] inet_release+0xed/0x1c0 [ 245.163922] sock_release+0x8d/0x1e0 [ 245.167605] ? sock_release+0x1e0/0x1e0 [ 245.171546] sock_close+0x16/0x20 [ 245.174970] __fput+0x327/0x7e0 [ 245.178229] ? fput+0x140/0x140 [ 245.181480] ? do_raw_spin_trylock+0x190/0x190 [ 245.186031] ? check_same_owner+0x320/0x320 [ 245.190322] ____fput+0x15/0x20 [ 245.193573] task_work_run+0x18a/0x260 [ 245.197432] ? task_work_cancel+0x210/0x210 [ 245.201736] ? _raw_spin_unlock+0x22/0x30 [ 245.205853] ? switch_task_namespaces+0x87/0xc0 [ 245.210499] do_exit+0xa3a/0x1b10 [ 245.213921] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 245.219082] ? print_usage_bug+0x480/0x480 [ 245.223291] ? mm_update_next_owner+0x930/0x930 [ 245.227926] ? check_noncircular+0x20/0x20 [ 245.232129] ? check_noncircular+0x20/0x20 [ 245.236337] ? find_held_lock+0x35/0x1d0 [ 245.240369] ? find_held_lock+0x35/0x1d0 [ 245.244412] ? check_noncircular+0x20/0x20 [ 245.248633] ? check_noncircular+0x20/0x20 [ 245.252842] ? lock_downgrade+0x990/0x990 [ 245.256960] ? do_raw_spin_trylock+0x190/0x190 [ 245.261513] ? reacquire_held_locks+0x1fd/0x3d0 [ 245.266146] ? mark_held_locks+0xaf/0x100 [ 245.270260] ? reacquire_held_locks+0x1fd/0x3d0 [ 245.274897] ? check_noncircular+0x20/0x20 [ 245.279100] ? find_held_lock+0x35/0x1d0 [ 245.283135] ? release_sock+0x1d4/0x2a0 [ 245.287077] ? lock_downgrade+0x990/0x990 [ 245.291192] ? lock_downgrade+0x990/0x990 [ 245.295312] ? find_held_lock+0x35/0x1d0 [ 245.299352] ? get_signal+0x855/0x17e0 [ 245.303207] ? lock_downgrade+0x990/0x990 [ 245.307330] do_group_exit+0x149/0x400 [ 245.311186] ? __lock_is_held+0xb6/0x140 [ 245.315213] ? SyS_exit+0x30/0x30 [ 245.318636] ? _raw_spin_unlock_irq+0x27/0x70 [ 245.323101] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 245.328088] get_signal+0x7e8/0x17e0 [ 245.331797] ? ptrace_notify+0x130/0x130 [ 245.335825] ? inet_autobind+0x1f/0x180 [ 245.339769] ? __local_bh_enable_ip+0x9d/0x160 [ 245.344321] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 245.349313] ? release_sock+0x1d4/0x2a0 [ 245.353252] ? trace_hardirqs_on+0xd/0x10 [ 245.357365] ? __local_bh_enable_ip+0x9d/0x160 [ 245.361918] ? _raw_spin_unlock_bh+0x30/0x40 [ 245.366299] ? release_sock+0x1d4/0x2a0 [ 245.370242] ? __release_sock+0x360/0x360 [ 245.374358] ? trace_hardirqs_on+0xd/0x10 [ 245.378488] do_signal+0x94/0x1ee0 [ 245.382009] ? inet_sendmsg+0x11f/0x5e0 [ 245.385947] ? inet_sendmsg+0x126/0x5e0 [ 245.389895] ? __might_sleep+0x95/0x190 [ 245.393847] ? setup_sigcontext+0x7d0/0x7d0 [ 245.398136] ? selinux_socket_sendmsg+0x36/0x40 [ 245.402770] ? security_socket_sendmsg+0x89/0xb0 [ 245.407494] ? inet_recvmsg+0x5f0/0x5f0 [ 245.411438] ? sock_sendmsg+0x4f/0x110 [ 245.415293] ? fput+0xd2/0x140 [ 245.418453] ? SYSC_sendto+0x40d/0x5a0 [ 245.422311] ? SYSC_connect+0x470/0x470 [ 245.426257] ? find_held_lock+0x35/0x1d0 [ 245.430289] ? exit_to_usermode_loop+0x98/0x300 [ 245.434931] exit_to_usermode_loop+0x224/0x300 [ 245.439486] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 245.444997] ? handle_mm_fault+0x4a2/0x860 [ 245.449198] ? down_read_trylock+0xdb/0x170 [ 245.453496] syscall_return_slowpath+0x3a7/0x450 [ 245.458218] ? prepare_exit_to_usermode+0x220/0x220 [ 245.463205] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 245.468110] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 245.473093] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 245.477830] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 245.482552] RIP: 0033:0x447419 [ 245.485707] RSP: 002b:00007fe9f7320db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 245.493386] RAX: 000000000000001a RBX: 0000000000000000 RCX: 0000000000447419 [ 245.500621] RDX: 000000000000001a RSI: 0000000020b54fe6 RDI: 0000000000000003 [ 245.507855] RBP: 0000000000000000 R08: 0000000020b54000 R09: 0000000000000010 [ 245.515092] R10: 0000000000000004 R11: 0000000000000212 R12: 0000000000000000 [ 245.522328] R13: 00000000007efd4f R14: 00007fe9f73219c0 R15: 0000000000000000 [ 245.529977] Dumping ftrace buffer: [ 245.533528] (ftrace buffer empty) [ 245.537208] Kernel Offset: disabled [ 245.540802] Rebooting in 86400 seconds..