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-1,10.128.0.53' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 44.587571] refcount_t: underflow; use-after-free. [ 44.588461] ------------[ cut here ]------------ [ 44.589231] WARNING: CPU: 0 PID: 2999 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 44.590411] Kernel panic - not syncing: panic_on_warn set ... [ 44.590411] [ 44.591385] CPU: 0 PID: 2999 Comm: syzkaller459202 Not tainted 4.14.0-rc1+ #70 [ 44.592355] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.593577] Call Trace: [ 44.593943] dump_stack+0x194/0x257 [ 44.594455] ? arch_local_irq_restore+0x53/0x53 [ 44.595091] panic+0x1e4/0x417 [ 44.595575] ? __warn+0x1d9/0x1d9 [ 44.596045] ? show_regs_print_info+0x65/0x65 [ 44.596662] ? refcount_sub_and_test+0x167/0x1b0 [ 44.597297] __warn+0x1c4/0x1d9 [ 44.597744] ? refcount_sub_and_test+0x167/0x1b0 [ 44.598384] report_bug+0x211/0x2d0 [ 44.598884] fixup_bug+0x40/0x90 [ 44.599344] do_trap+0x260/0x390 [ 44.599813] do_error_trap+0x120/0x390 [ 44.600343] ? do_trap+0x390/0x390 [ 44.600824] ? refcount_sub_and_test+0x167/0x1b0 [ 44.601536] ? vprintk_emit+0x3ea/0x590 [ 44.602101] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 44.602754] do_invalid_op+0x1b/0x20 [ 44.603259] invalid_op+0x18/0x20 [ 44.603790] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 44.604504] RSP: 0018:ffff8801ce47e3e0 EFLAGS: 00010282 [ 44.605219] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 44.606175] RDX: 0000000000000026 RSI: 1ffff10039c8fc3c RDI: ffffed0039c8fc70 [ 44.607130] RBP: ffff8801ce47e470 R08: ffff8801ce47dad0 R09: 0000000000000000 [ 44.610611] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039c8fc7d [ 44.617853] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801c038aa24 [ 44.625120] ? refcount_inc+0x50/0x50 [ 44.628894] ? __sctp_outq_teardown+0xa5b/0x1230 [ 44.633620] ? sctp_association_free+0x2d0/0x930 [ 44.638568] ? sctp_do_sm+0x271b/0x6a30 [ 44.642525] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 44.647250] ? sctp_close+0x3c6/0x980 [ 44.651017] ? inet_release+0xed/0x1c0 [ 44.654880] sctp_wfree+0x183/0x620 [ 44.658480] ? __sctp_write_space+0x910/0x910 [ 44.662949] skb_release_head_state+0x124/0x200 [ 44.667589] skb_release_all+0x15/0x60 [ 44.671448] consume_skb+0x153/0x490 [ 44.675131] ? sctp_chunk_put+0x99/0x420 [ 44.679162] ? alloc_skb_with_frags+0x750/0x750 [ 44.683802] ? sctp_chunk_hold+0x20/0x20 [ 44.687839] ? refcount_sub_and_test+0x115/0x1b0 [ 44.692569] ? refcount_inc+0x50/0x50 [ 44.696341] ? mark_held_locks+0xb2/0x100 [ 44.700463] ? sctp_datamsg_put+0x456/0x560 [ 44.704761] sctp_chunk_put+0x29c/0x420 [ 44.708709] ? sctp_chunk_hold+0x20/0x20 [ 44.712745] ? sctp_transport_dst_confirm+0x50/0x50 [ 44.717734] ? sctp_sched_fcfs_dequeue+0x198/0x290 [ 44.722637] ? sctp_sched_dequeue_common+0x5d0/0x5d0 [ 44.727719] sctp_chunk_free+0x53/0x60 [ 44.731578] __sctp_outq_teardown+0xa5b/0x1230 [ 44.736138] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 44.741040] ? copy_trace+0x1d0/0x1d0 [ 44.744817] ? check_noncircular+0x20/0x20 [ 44.749020] ? check_noncircular+0x20/0x20 [ 44.753226] ? unwind_get_return_address+0x61/0xa0 [ 44.758127] ? __save_stack_trace+0x61/0xd0 [ 44.762418] ? check_noncircular+0x20/0x20 [ 44.766623] ? print_usage_bug+0x480/0x480 [ 44.770832] ? find_held_lock+0x39/0x1d0 [ 44.774873] ? lock_downgrade+0x990/0x990 [ 44.778996] ? sk_dst_check+0x560/0x560 [ 44.782939] ? rcu_read_lock_sched_held+0x108/0x120 [ 44.787932] ? lock_release+0xd70/0xd70 [ 44.791883] sctp_outq_free+0x15/0x20 [ 44.795653] sctp_association_free+0x2d0/0x930 [ 44.800209] ? sctp_asconf_queue_teardown+0x700/0x700 [ 44.805366] ? sock_def_wakeup+0x222/0x350 [ 44.809570] ? sk_dst_check+0x560/0x560 [ 44.813513] ? sctp_association_put+0x74/0x2f0 [ 44.818062] ? sctp_association_hold+0x20/0x20 [ 44.822616] ? unwind_get_return_address+0x61/0xa0 [ 44.827517] ? sctp_sm_lookup_event+0x95/0x3c0 [ 44.832073] sctp_do_sm+0x271b/0x6a30 [ 44.835848] ? do_exit+0xa52/0x1b40 [ 44.839457] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 44.845489] ? print_usage_bug+0x480/0x480 [ 44.849696] ? print_usage_bug+0x480/0x480 [ 44.853903] ? find_held_lock+0x39/0x1d0 [ 44.857943] ? lock_downgrade+0x990/0x990 [ 44.862067] ? skb_dequeue+0x22/0x180 [ 44.865843] ? do_raw_spin_trylock+0x190/0x190 [ 44.870400] ? mark_held_locks+0xb2/0x100 [ 44.874526] ? trace_hardirqs_on+0xd/0x10 [ 44.878652] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 44.883208] sctp_close+0x3c6/0x980 [ 44.886811] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 44.892056] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 44.897044] ? trace_hardirqs_on+0xd/0x10 [ 44.901171] ? rcu_eqs_enter_common.constprop.73+0x270/0x270 [ 44.906943] ? locks_remove_file+0x3fa/0x5a0 [ 44.911326] ? fcntl_setlk+0x10d0/0x10d0 [ 44.915357] ? lock_downgrade+0x990/0x990 [ 44.919478] ? __fsnotify_parent+0xb4/0x3a0 [ 44.923769] ? ip_mc_drop_socket+0x1ce/0x230 [ 44.928150] inet_release+0xed/0x1c0 [ 44.931835] sock_release+0x8d/0x1e0 [ 44.935518] ? sock_release+0x1e0/0x1e0 [ 44.939459] sock_close+0x16/0x20 [ 44.942879] __fput+0x333/0x7f0 [ 44.946132] ? fput+0x140/0x140 [ 44.949385] ? check_same_owner+0x320/0x320 [ 44.953682] ____fput+0x15/0x20 [ 44.956931] task_work_run+0x199/0x270 [ 44.960791] ? task_work_cancel+0x210/0x210 [ 44.965080] ? free_nsproxy+0x185/0x1f0 [ 44.969024] ? switch_task_namespaces+0xa2/0xc0 [ 44.973667] do_exit+0xa52/0x1b40 [ 44.977091] ? print_usage_bug+0x480/0x480 [ 44.981296] ? __sched_text_start+0x8/0x8 [ 44.985423] ? mm_update_next_owner+0x930/0x930 [ 44.990062] ? find_held_lock+0x39/0x1d0 [ 44.994098] ? check_noncircular+0x20/0x20 [ 44.998302] ? check_noncircular+0x20/0x20 [ 45.002504] ? lock_downgrade+0x990/0x990 [ 45.006634] ? reacquire_held_locks+0x205/0x3d0 [ 45.011270] ? check_noncircular+0x20/0x20 [ 45.015473] ? find_held_lock+0x39/0x1d0 [ 45.019517] ? lock_downgrade+0x990/0x990 [ 45.023632] ? lock_downgrade+0x990/0x990 [ 45.027753] ? find_held_lock+0x39/0x1d0 [ 45.031794] ? lock_downgrade+0x990/0x990 [ 45.035914] ? recalc_sigpending_tsk+0x117/0x150 [ 45.040640] ? recalc_sigpending+0x103/0x160 [ 45.045015] ? recalc_sigpending_tsk+0x150/0x150 [ 45.049739] ? get_signal+0x397/0x17e0 [ 45.053607] do_group_exit+0x149/0x400 [ 45.057462] ? __lock_is_held+0xbc/0x140 [ 45.061490] ? SyS_exit+0x30/0x30 [ 45.064911] ? _raw_spin_unlock_irq+0x27/0x70 [ 45.069377] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 45.074369] get_signal+0x7e8/0x17e0 [ 45.078078] ? ptrace_notify+0x130/0x130 [ 45.082112] ? lock_downgrade+0x990/0x990 [ 45.086238] ? __might_fault+0xe0/0x1d0 [ 45.090188] ? selinux_tun_dev_create+0xc0/0xc0 [ 45.094833] do_signal+0x94/0x1ee0 [ 45.098346] ? inet_sendmsg+0x11f/0x5e0 [ 45.102287] ? inet_sendmsg+0x126/0x5e0 [ 45.106234] ? __might_sleep+0x95/0x190 [ 45.110180] ? setup_sigcontext+0x7d0/0x7d0 [ 45.114473] ? selinux_socket_sendmsg+0x36/0x40 [ 45.119114] ? security_socket_sendmsg+0x89/0xb0 [ 45.123838] ? inet_recvmsg+0x5f0/0x5f0 [ 45.127784] ? sock_sendmsg+0x4f/0x110 [ 45.131641] ? fput+0xd2/0x140 [ 45.134802] ? SYSC_sendto+0x413/0x5a0 [ 45.138661] ? SYSC_connect+0x480/0x480 [ 45.142602] ? __handle_mm_fault+0x39c0/0x39c0 [ 45.147155] ? vmacache_update+0xfe/0x130 [ 45.151278] ? exit_to_usermode_loop+0x98/0x300 [ 45.155922] exit_to_usermode_loop+0x224/0x300 [ 45.160475] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 45.165982] ? __do_page_fault+0xb60/0xb60 [ 45.170185] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 45.175173] syscall_return_slowpath+0x42f/0x500 [ 45.179894] ? finish_task_switch+0x1aa/0x740 [ 45.184361] ? prepare_exit_to_usermode+0x2c0/0x2c0 [ 45.189350] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 45.194251] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 45.199237] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 45.203967] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 45.208688] RIP: 0033:0x445e89 [ 45.211844] RSP: 002b:00007f203d681db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 45.219523] RAX: 000000000000001a RBX: 0000000000000000 RCX: 0000000000445e89 [ 45.226763] RDX: 000000000000001a RSI: 0000000020001f98 RDI: 0000000000000003 [ 45.234002] RBP: 0000000000000000 R08: 0000000020944000 R09: 0000000000000010 [ 45.241241] R10: 0000000000000001 R11: 0000000000000212 R12: 0000000000000000 [ 45.248481] R13: 00000000007efe5f R14: 00007f203d6829c0 R15: 0000000000000000 [ 45.255901] Dumping ftrace buffer: [ 45.259469] (ftrace buffer empty) [ 45.263152] Kernel Offset: disabled [ 45.266759] Rebooting in 86400 seconds..