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-8,10.128.0.6' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 31.475280] refcount_t: underflow; use-after-free. [ 31.480839] ------------[ cut here ]------------ [ 31.485832] WARNING: CPU: 1 PID: 2990 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 31.494526] Kernel panic - not syncing: panic_on_warn set ... [ 31.494526] [ 31.501864] CPU: 1 PID: 2990 Comm: syzkaller406200 Not tainted 4.14.0-rc1+ #58 [ 31.509199] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.518521] Call Trace: [ 31.521083] dump_stack+0x194/0x257 [ 31.524689] ? arch_local_irq_restore+0x53/0x53 [ 31.529342] panic+0x1e4/0x417 [ 31.532511] ? __warn+0x1d9/0x1d9 [ 31.535935] ? show_regs_print_info+0x65/0x65 [ 31.540420] ? refcount_sub_and_test+0x167/0x1b0 [ 31.545147] __warn+0x1c4/0x1d9 [ 31.548399] ? refcount_sub_and_test+0x167/0x1b0 [ 31.553126] report_bug+0x211/0x2d0 [ 31.556731] fixup_bug+0x40/0x90 [ 31.560069] do_trap+0x260/0x390 [ 31.563410] do_error_trap+0x120/0x390 [ 31.567271] ? do_trap+0x390/0x390 [ 31.570790] ? refcount_sub_and_test+0x167/0x1b0 [ 31.575514] ? vprintk_emit+0x3ea/0x590 [ 31.579466] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.584283] do_invalid_op+0x1b/0x20 [ 31.587967] invalid_op+0x18/0x20 [ 31.591389] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 31.596724] RSP: 0018:ffff8801ce706300 EFLAGS: 00010282 [ 31.602058] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 31.609297] RDX: 0000000000000026 RSI: 1ffff10039ce0c20 RDI: ffffed0039ce0c54 [ 31.616543] RBP: ffff8801ce706390 R08: ffff8801ce7059f0 R09: 0000000000000000 [ 31.623780] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039ce0c61 [ 31.631027] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801ce619364 [ 31.638291] ? refcount_inc+0x50/0x50 [ 31.642059] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 31.646786] ? sctp_association_free+0x2d0/0x930 [ 31.651508] ? sctp_do_sm+0x28e7/0x6dd0 [ 31.655462] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 31.660188] ? sctp_close+0x3c6/0x980 [ 31.663958] ? inet_release+0xed/0x1c0 [ 31.667822] sctp_wfree+0x183/0x620 [ 31.671420] ? __sctp_write_space+0x910/0x910 [ 31.675891] skb_release_head_state+0x124/0x200 [ 31.680531] skb_release_all+0x15/0x60 [ 31.684389] consume_skb+0x153/0x490 [ 31.688073] ? sctp_chunk_put+0x99/0x420 [ 31.692104] ? alloc_skb_with_frags+0x710/0x710 [ 31.696742] ? sctp_chunk_hold+0x20/0x20 [ 31.700776] ? refcount_sub_and_test+0x115/0x1b0 [ 31.705509] ? refcount_inc+0x50/0x50 [ 31.709280] ? mark_held_locks+0xb2/0x100 [ 31.713401] ? sctp_datamsg_put+0x456/0x560 [ 31.717705] sctp_chunk_put+0x29c/0x420 [ 31.721649] ? sctp_chunk_hold+0x20/0x20 [ 31.725686] ? sctp_transport_dst_confirm+0x50/0x50 [ 31.730687] sctp_chunk_free+0x53/0x60 [ 31.734546] __sctp_outq_teardown+0xc7d/0x15a0 [ 31.739100] ? inet6_release+0x50/0x70 [ 31.742964] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 31.747873] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 31.752861] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 31.757846] ? unwind_dump+0x4c0/0x4c0 [ 31.761706] ? unwind_dump+0x4c0/0x4c0 [ 31.765568] ? copy_trace+0x1d0/0x1d0 [ 31.769354] ? check_noncircular+0x20/0x20 [ 31.773557] ? check_noncircular+0x20/0x20 [ 31.777760] ? unwind_get_return_address+0x61/0xa0 [ 31.782667] ? __save_stack_trace+0x61/0xd0 [ 31.786958] ? check_noncircular+0x20/0x20 [ 31.791171] ? print_usage_bug+0x480/0x480 [ 31.795381] ? find_held_lock+0x39/0x1d0 [ 31.799422] ? lock_downgrade+0x990/0x990 [ 31.803547] ? sk_dst_check+0x560/0x560 [ 31.807491] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.812487] ? lock_release+0xd70/0xd70 [ 31.816438] sctp_outq_free+0x15/0x20 [ 31.820214] sctp_association_free+0x2d0/0x930 [ 31.824775] ? sctp_asconf_queue_teardown+0x700/0x700 [ 31.829945] ? sock_def_wakeup+0x222/0x350 [ 31.834150] ? sk_dst_check+0x560/0x560 [ 31.838098] ? sctp_association_put+0x74/0x2f0 [ 31.842651] ? sctp_association_hold+0x20/0x20 [ 31.847202] ? unwind_dump+0x4c0/0x4c0 [ 31.851061] ? sctp_sm_lookup_event+0x95/0x3c0 [ 31.855624] sctp_do_sm+0x28e7/0x6dd0 [ 31.859408] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 31.865447] ? print_usage_bug+0x480/0x480 [ 31.869648] ? __lock_acquire+0x20fd/0x4620 [ 31.874032] ? print_usage_bug+0x480/0x480 [ 31.878237] ? find_held_lock+0x39/0x1d0 [ 31.882278] ? lock_downgrade+0x990/0x990 [ 31.886404] ? skb_dequeue+0x22/0x180 [ 31.890180] ? do_raw_spin_trylock+0x190/0x190 [ 31.894741] ? mark_held_locks+0xb2/0x100 [ 31.898866] ? trace_hardirqs_on+0xd/0x10 [ 31.902997] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 31.907553] sctp_close+0x3c6/0x980 [ 31.911160] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 31.916403] ? unwind_get_return_address+0x61/0xa0 [ 31.921304] ? check_noncircular+0x20/0x20 [ 31.925519] ? depot_save_stack+0x3b5/0x490 [ 31.929815] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 31.934282] ? ipv6_sock_mc_close+0x148/0x1a0 [ 31.938745] ? ipv6_sock_ac_drop+0x580/0x580 [ 31.943122] ? ip_mc_drop_socket+0x1ce/0x230 [ 31.947509] ? __fsnotify_parent+0xb4/0x3a0 [ 31.951804] inet_release+0xed/0x1c0 [ 31.955490] inet6_release+0x50/0x70 [ 31.959175] sock_release+0x8d/0x1e0 [ 31.962864] ? sock_release+0x1e0/0x1e0 [ 31.966809] sock_close+0x16/0x20 [ 31.970231] __fput+0x333/0x7f0 [ 31.973485] ? fput+0x140/0x140 [ 31.976737] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.981211] ____fput+0x15/0x20 [ 31.984466] task_work_run+0x199/0x270 [ 31.988324] ? task_work_cancel+0x210/0x210 [ 31.992614] ? _raw_spin_unlock+0x22/0x30 [ 31.996733] ? switch_task_namespaces+0x87/0xc0 [ 32.001382] do_exit+0xa52/0x1b40 [ 32.004819] ? mm_update_next_owner+0x930/0x930 [ 32.009454] ? find_held_lock+0x39/0x1d0 [ 32.013493] ? lock_downgrade+0x990/0x990 [ 32.017613] ? lock_downgrade+0x990/0x990 [ 32.021741] ? release_sock+0x74/0x2a0 [ 32.025605] ? check_noncircular+0x20/0x20 [ 32.029808] ? sctp_association_hold+0x20/0x20 [ 32.034359] ? trace_hardirqs_on+0xd/0x10 [ 32.038482] ? __local_bh_enable_ip+0x9d/0x160 [ 32.043035] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.048023] ? trace_hardirqs_on+0xd/0x10 [ 32.052141] ? __local_bh_enable_ip+0x9d/0x160 [ 32.056700] ? find_held_lock+0x39/0x1d0 [ 32.060743] ? lock_downgrade+0x990/0x990 [ 32.064861] ? recalc_sigpending_tsk+0x117/0x150 [ 32.069589] ? recalc_sigpending+0x103/0x160 [ 32.073977] ? recalc_sigpending_tsk+0x150/0x150 [ 32.078701] ? get_signal+0x397/0x17e0 [ 32.082571] do_group_exit+0x149/0x400 [ 32.086427] ? __lock_is_held+0xbc/0x140 [ 32.090457] ? SyS_exit+0x30/0x30 [ 32.093880] ? _raw_spin_unlock_irq+0x27/0x70 [ 32.098346] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.103334] get_signal+0x7e8/0x17e0 [ 32.107062] ? ptrace_notify+0x130/0x130 [ 32.111096] ? inet_sendmsg+0x126/0x5e0 [ 32.115045] ? rcu_pm_notify+0xc0/0xc0 [ 32.118913] ? inet_recvmsg+0x5f0/0x5f0 [ 32.122865] ? ___sys_sendmsg+0x4a0/0x8a0 [ 32.126983] ? rcu_read_lock_sched_held+0x108/0x120 [ 32.131973] ? ___sys_sendmsg+0x4a5/0x8a0 [ 32.136097] do_signal+0x94/0x1ee0 [ 32.139604] ? copy_msghdr_from_user+0x590/0x590 [ 32.144329] ? wake_up_q+0x8a/0xe0 [ 32.147847] ? setup_sigcontext+0x7d0/0x7d0 [ 32.152158] ? down_read+0xa4/0x150 [ 32.155769] ? call_rwsem_wake+0x1b/0x30 [ 32.159804] ? exit_to_usermode_loop+0x98/0x300 [ 32.164447] exit_to_usermode_loop+0x224/0x300 [ 32.169002] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 32.174510] ? __do_page_fault+0xb60/0xb60 [ 32.178712] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.183713] syscall_return_slowpath+0x42f/0x500 [ 32.188451] ? finish_task_switch+0x1aa/0x740 [ 32.192927] ? prepare_exit_to_usermode+0x2c0/0x2c0 [ 32.197933] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 32.202832] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 32.207819] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 32.212548] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 32.217271] RIP: 0033:0x445609 [ 32.220436] RSP: 002b:00007f4802221dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e [ 32.228116] RAX: 000000000000000e RBX: 0000000000000000 RCX: 0000000000445609 [ 32.235355] RDX: 0000000000040000 RSI: 0000000020ee7000 RDI: 0000000000000003 [ 32.242594] RBP: 0000000000000000 R08: 00007f4802222700 R09: 00007f4802222700 [ 32.249844] R10: 00007f4802222700 R11: 0000000000000202 R12: 0000000000000000 [ 32.257091] R13: 00007ffe40ff8a5f R14: 00007f48022229c0 R15: 0000000000000000 [ 32.264903] Dumping ftrace buffer: [ 32.268467] (ftrace buffer empty) [ 32.272149] Kernel Offset: disabled [ 32.275762] Rebooting in 86400 seconds..