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-kasan-gce-8,10.128.0.6' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 41.043098] refcount_t: underflow; use-after-free. [ 41.043998] ------------[ cut here ]------------ [ 41.044853] WARNING: CPU: 1 PID: 3010 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 41.046034] Kernel panic - not syncing: panic_on_warn set ... [ 41.046034] [ 41.047027] CPU: 1 PID: 3010 Comm: syzkaller188109 Not tainted 4.13.0-rc5+ #43 [ 41.048074] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.049343] Call Trace: [ 41.049706] dump_stack+0x194/0x257 [ 41.050252] ? arch_local_irq_restore+0x53/0x53 [ 41.050939] panic+0x1e4/0x417 [ 41.051392] ? __warn+0x1d9/0x1d9 [ 41.051873] ? show_regs_print_info+0x65/0x65 [ 41.052484] ? refcount_sub_and_test+0x167/0x1b0 [ 41.053116] __warn+0x1c4/0x1d9 [ 41.053589] ? refcount_sub_and_test+0x167/0x1b0 [ 41.054236] report_bug+0x211/0x2d0 [ 41.054774] fixup_bug+0x40/0x90 [ 41.055231] do_trap+0x260/0x390 [ 41.055745] do_error_trap+0x120/0x390 [ 41.056270] ? do_trap+0x390/0x390 [ 41.056779] ? refcount_sub_and_test+0x167/0x1b0 [ 41.057464] ? vprintk_emit+0x3ea/0x590 [ 41.058061] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 41.058748] do_invalid_op+0x1b/0x20 [ 41.059249] invalid_op+0x1e/0x30 [ 41.059712] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 41.060419] RSP: 0018:ffff8801d0226310 EFLAGS: 00010282 [ 41.061129] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 41.062081] RDX: 0000000000000026 RSI: 1ffff1003a044c22 RDI: ffffed003a044c56 [ 41.063136] RBP: ffff8801d02263a0 R08: 0000000000000001 R09: 0000000000000000 [ 41.069749] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a044c63 [ 41.077101] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d0637a3c [ 41.084379] ? refcount_inc+0x50/0x50 [ 41.088153] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 41.092888] ? sctp_association_free+0x2d0/0x930 [ 41.097629] ? sctp_do_sm+0x28e7/0x6d90 [ 41.101599] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 41.106338] ? sctp_close+0x3c6/0x980 [ 41.110120] ? inet_release+0xed/0x1c0 [ 41.114009] sctp_wfree+0x183/0x620 [ 41.117620] ? __sctp_write_space+0x910/0x910 [ 41.122101] skb_release_head_state+0x124/0x200 [ 41.126754] skb_release_all+0x15/0x60 [ 41.130617] consume_skb+0x153/0x490 [ 41.134311] ? sctp_chunk_put+0x99/0x420 [ 41.138354] ? pskb_carve+0x1db0/0x1db0 [ 41.142309] ? sctp_chunk_hold+0x20/0x20 [ 41.146354] ? refcount_sub_and_test+0x115/0x1b0 [ 41.151085] ? refcount_inc+0x50/0x50 [ 41.154864] ? mark_held_locks+0xaf/0x100 [ 41.158988] ? sctp_datamsg_put+0x456/0x560 [ 41.163301] sctp_chunk_put+0x29c/0x420 [ 41.167265] ? sctp_chunk_hold+0x20/0x20 [ 41.171309] ? sctp_transport_dst_confirm+0x50/0x50 [ 41.176300] ? noop_count+0x40/0x40 [ 41.179906] sctp_chunk_free+0x53/0x60 [ 41.183764] __sctp_outq_teardown+0xc7d/0x15a0 [ 41.188322] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 41.193219] ? lock_downgrade+0x990/0x990 [ 41.197337] ? lock_release+0xa40/0xa40 [ 41.201280] ? __free_insn_slot+0x5c0/0x5c0 [ 41.205570] ? update_stack_state+0x700/0x700 [ 41.210031] ? print_usage_bug+0x480/0x480 [ 41.214242] ? is_bpf_text_address+0xa4/0x120 [ 41.218704] ? __kernel_text_address+0xae/0xe0 [ 41.223252] ? unwind_get_return_address+0x61/0xa0 [ 41.228150] ? __save_stack_trace+0x7e/0xd0 [ 41.232451] ? check_noncircular+0x20/0x20 [ 41.236660] ? print_usage_bug+0x480/0x480 [ 41.240859] ? SOFTIRQ_verbose+0x10/0x10 [ 41.244882] ? save_stack_trace+0x16/0x20 [ 41.249001] ? save_trace+0x11f/0x350 [ 41.252776] ? lock_acquire+0x1d5/0x580 [ 41.256729] ? lock_acquire+0x1d5/0x580 [ 41.260671] ? lock_timer_base+0x1a3/0x2b0 [ 41.264878] ? find_held_lock+0x35/0x1d0 [ 41.268915] ? sock_def_wakeup+0x1f9/0x350 [ 41.273118] ? lock_downgrade+0x990/0x990 [ 41.277235] ? lock_release+0xa40/0xa40 [ 41.281191] sctp_outq_free+0x15/0x20 [ 41.284968] sctp_association_free+0x2d0/0x930 [ 41.289528] ? sctp_asconf_queue_teardown+0x700/0x700 [ 41.294685] ? sock_def_wakeup+0x222/0x350 [ 41.298888] ? sk_dst_check+0x560/0x560 [ 41.302830] ? sctp_association_put+0x74/0x2f0 [ 41.307379] ? sctp_association_hold+0x20/0x20 [ 41.311925] ? print_usage_bug+0x480/0x480 [ 41.316139] ? sctp_sm_lookup_event+0x95/0x3c0 [ 41.320689] sctp_do_sm+0x28e7/0x6d90 [ 41.324456] ? check_noncircular+0x20/0x20 [ 41.328671] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 41.334701] ? print_usage_bug+0x480/0x480 [ 41.338904] ? exit_to_usermode_loop+0x224/0x300 [ 41.343625] ? syscall_return_slowpath+0x3a7/0x450 [ 41.348525] ? print_usage_bug+0x480/0x480 [ 41.352727] ? find_held_lock+0x35/0x1d0 [ 41.356769] ? find_held_lock+0x35/0x1d0 [ 41.360805] ? skb_dequeue+0x12a/0x180 [ 41.364661] ? lock_downgrade+0x990/0x990 [ 41.368781] ? do_raw_spin_trylock+0x190/0x190 [ 41.373335] ? mark_held_locks+0xaf/0x100 [ 41.377459] ? trace_hardirqs_on+0xd/0x10 [ 41.381583] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 41.386137] sctp_close+0x3c6/0x980 [ 41.389738] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 41.394980] ? unwind_get_return_address+0x61/0xa0 [ 41.399886] ? trace_hardirqs_off+0xd/0x10 [ 41.404088] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 41.409156] ? check_noncircular+0x20/0x20 [ 41.413365] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 41.417829] ? ipv6_sock_mc_close+0x148/0x1a0 [ 41.422289] ? ipv6_sock_ac_drop+0x580/0x580 [ 41.426660] ? ip_mc_drop_socket+0x1ce/0x230 [ 41.431034] ? __fsnotify_parent+0xb4/0x3a0 [ 41.435333] inet_release+0xed/0x1c0 [ 41.439027] inet6_release+0x50/0x70 [ 41.442716] sock_release+0x8d/0x1e0 [ 41.446937] ? sock_release+0x1e0/0x1e0 [ 41.450875] sock_close+0x16/0x20 [ 41.454295] __fput+0x327/0x7e0 [ 41.457546] ? fput+0x140/0x140 [ 41.460809] ? do_raw_spin_trylock+0x190/0x190 [ 41.465361] ? check_same_owner+0x320/0x320 [ 41.469653] ____fput+0x15/0x20 [ 41.472906] task_work_run+0x18a/0x260 [ 41.476762] ? task_work_cancel+0x210/0x210 [ 41.481052] ? _raw_spin_unlock+0x22/0x30 [ 41.485165] ? switch_task_namespaces+0x87/0xc0 [ 41.489806] do_exit+0xa3a/0x1b10 [ 41.493237] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 41.498398] ? print_usage_bug+0x480/0x480 [ 41.502603] ? mm_update_next_owner+0x930/0x930 [ 41.507241] ? check_noncircular+0x20/0x20 [ 41.511446] ? check_noncircular+0x20/0x20 [ 41.515651] ? find_held_lock+0x35/0x1d0 [ 41.519683] ? find_held_lock+0x35/0x1d0 [ 41.523714] ? check_noncircular+0x20/0x20 [ 41.527914] ? check_noncircular+0x20/0x20 [ 41.532114] ? lock_downgrade+0x990/0x990 [ 41.536237] ? do_raw_spin_trylock+0x190/0x190 [ 41.540788] ? reacquire_held_locks+0x1fd/0x3d0 [ 41.545421] ? mark_held_locks+0xaf/0x100 [ 41.549532] ? reacquire_held_locks+0x1fd/0x3d0 [ 41.554170] ? check_noncircular+0x20/0x20 [ 41.558371] ? find_held_lock+0x35/0x1d0 [ 41.562404] ? release_sock+0x1d4/0x2a0 [ 41.566345] ? lock_downgrade+0x990/0x990 [ 41.570458] ? lock_downgrade+0x990/0x990 [ 41.574577] ? find_held_lock+0x35/0x1d0 [ 41.578610] ? get_signal+0x855/0x17e0 [ 41.582519] ? lock_downgrade+0x990/0x990 [ 41.586640] do_group_exit+0x149/0x400 [ 41.590496] ? __lock_is_held+0xb6/0x140 [ 41.594524] ? SyS_exit+0x30/0x30 [ 41.597943] ? _raw_spin_unlock_irq+0x27/0x70 [ 41.602406] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.607394] get_signal+0x7e8/0x17e0 [ 41.611108] ? ptrace_notify+0x130/0x130 [ 41.615135] ? inet_autobind+0x1f/0x180 [ 41.619075] ? __local_bh_enable_ip+0x9d/0x160 [ 41.623625] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.628607] ? release_sock+0x1d4/0x2a0 [ 41.632549] ? trace_hardirqs_on+0xd/0x10 [ 41.636667] ? __local_bh_enable_ip+0x9d/0x160 [ 41.641220] ? _raw_spin_unlock_bh+0x30/0x40 [ 41.645596] ? release_sock+0x1d4/0x2a0 [ 41.649548] ? trace_hardirqs_on+0xd/0x10 [ 41.653668] do_signal+0x94/0x1ee0 [ 41.657179] ? inet_sendmsg+0x11f/0x5e0 [ 41.661119] ? inet_sendmsg+0x126/0x5e0 [ 41.665058] ? __might_sleep+0x95/0x190 [ 41.669002] ? setup_sigcontext+0x7d0/0x7d0 [ 41.673291] ? selinux_socket_sendmsg+0x36/0x40 [ 41.677928] ? security_socket_sendmsg+0x89/0xb0 [ 41.682650] ? inet_recvmsg+0x5f0/0x5f0 [ 41.686593] ? sock_sendmsg+0x4f/0x110 [ 41.690447] ? fput+0xd2/0x140 [ 41.693608] ? SYSC_sendto+0x40d/0x5a0 [ 41.697466] ? SYSC_connect+0x470/0x470 [ 41.701414] ? find_held_lock+0x35/0x1d0 [ 41.705447] ? exit_to_usermode_loop+0x98/0x300 [ 41.710090] exit_to_usermode_loop+0x224/0x300 [ 41.714651] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 41.720156] ? handle_mm_fault+0x4a2/0x860 [ 41.724358] ? down_read_trylock+0xdb/0x170 [ 41.728652] syscall_return_slowpath+0x3a7/0x450 [ 41.733385] ? prepare_exit_to_usermode+0x220/0x220 [ 41.738371] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 41.743278] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 41.748264] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 41.752992] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 41.757712] RIP: 0033:0x445469 [ 41.760872] RSP: 002b:00007faf6dff3db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 41.768552] RAX: 0000000000000006 RBX: 0000000000000000 RCX: 0000000000445469 [ 41.775803] RDX: 0000000000000006 RSI: 0000000020aa7000 RDI: 0000000000000003 [ 41.783041] RBP: 0000000000000000 R08: 0000000020aa7000 R09: 000000000000001c [ 41.790278] R10: 0000000000008000 R11: 0000000000000212 R12: 0000000000000000 [ 41.797514] R13: 00007ffecc67b44f R14: 00007faf6dff49c0 R15: 0000000000000000 [ 41.805429] Dumping ftrace buffer: [ 41.809058] (ftrace buffer empty) [ 41.812744] Kernel Offset: disabled [ 41.816356] Rebooting in 86400 seconds..