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-6,10.128.0.24' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 43.248716] refcount_t: underflow; use-after-free. [ 43.249568] ------------[ cut here ]------------ [ 43.250381] WARNING: CPU: 0 PID: 3008 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 43.251599] Kernel panic - not syncing: panic_on_warn set ... [ 43.251599] [ 43.252671] CPU: 0 PID: 3008 Comm: syzkaller773749 Not tainted 4.13.0-rc5+ #43 [ 43.253675] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.254909] Call Trace: [ 43.255299] dump_stack+0x194/0x257 [ 43.255806] ? arch_local_irq_restore+0x53/0x53 [ 43.256449] panic+0x1e4/0x417 [ 43.256912] ? __warn+0x1d9/0x1d9 [ 43.257421] ? show_regs_print_info+0x65/0x65 [ 43.258029] ? refcount_sub_and_test+0x167/0x1b0 [ 43.258679] __warn+0x1c4/0x1d9 [ 43.259120] ? refcount_sub_and_test+0x167/0x1b0 [ 43.259918] report_bug+0x211/0x2d0 [ 43.260408] fixup_bug+0x40/0x90 [ 43.260934] do_trap+0x260/0x390 [ 43.261410] do_error_trap+0x120/0x390 [ 43.261932] ? do_trap+0x390/0x390 [ 43.262407] ? refcount_sub_and_test+0x167/0x1b0 [ 43.263036] ? vprintk_emit+0x3ea/0x590 [ 43.263573] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.264324] do_invalid_op+0x1b/0x20 [ 43.264823] invalid_op+0x1e/0x30 [ 43.265286] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 43.266074] RSP: 0018:ffff8801cfc26310 EFLAGS: 00010282 [ 43.266835] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 43.267889] RDX: 0000000000000026 RSI: 1ffff10039f84c22 RDI: ffffed0039f84c56 [ 43.268919] RBP: ffff8801cfc263a0 R08: 0000000000000001 R09: 0000000000000000 [ 43.276169] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039f84c63 [ 43.283402] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d051ca3c [ 43.290660] ? refcount_inc+0x50/0x50 [ 43.294428] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 43.299149] ? sctp_association_free+0x2d0/0x930 [ 43.303888] ? sctp_do_sm+0x28e7/0x6d90 [ 43.307830] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 43.312556] ? sctp_close+0x3c6/0x980 [ 43.316333] ? inet_release+0xed/0x1c0 [ 43.320197] sctp_wfree+0x183/0x620 [ 43.323793] ? __sctp_write_space+0x910/0x910 [ 43.328260] skb_release_head_state+0x124/0x200 [ 43.332898] skb_release_all+0x15/0x60 [ 43.336755] consume_skb+0x153/0x490 [ 43.340458] ? sctp_chunk_put+0x99/0x420 [ 43.344491] ? pskb_carve+0x1db0/0x1db0 [ 43.348451] ? sctp_chunk_hold+0x20/0x20 [ 43.352487] ? refcount_sub_and_test+0x115/0x1b0 [ 43.357336] ? refcount_inc+0x50/0x50 [ 43.361111] ? mark_held_locks+0xaf/0x100 [ 43.365237] ? sctp_datamsg_put+0x456/0x560 [ 43.369545] sctp_chunk_put+0x29c/0x420 [ 43.373488] ? sctp_chunk_hold+0x20/0x20 [ 43.377542] ? sctp_transport_dst_confirm+0x50/0x50 [ 43.382534] ? noop_count+0x40/0x40 [ 43.386137] sctp_chunk_free+0x53/0x60 [ 43.390004] __sctp_outq_teardown+0xc7d/0x15a0 [ 43.394563] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 43.399458] ? lock_downgrade+0x990/0x990 [ 43.403574] ? lock_release+0xa40/0xa40 [ 43.407513] ? __free_insn_slot+0x5c0/0x5c0 [ 43.411800] ? update_stack_state+0x700/0x700 [ 43.416265] ? print_usage_bug+0x480/0x480 [ 43.420513] ? is_bpf_text_address+0xa4/0x120 [ 43.424996] ? __kernel_text_address+0xae/0xe0 [ 43.429545] ? unwind_get_return_address+0x61/0xa0 [ 43.434466] ? __save_stack_trace+0x7e/0xd0 [ 43.438759] ? check_noncircular+0x20/0x20 [ 43.442978] ? print_usage_bug+0x480/0x480 [ 43.447177] ? SOFTIRQ_verbose+0x10/0x10 [ 43.451201] ? save_stack_trace+0x16/0x20 [ 43.455314] ? save_trace+0x11f/0x350 [ 43.459087] ? lock_acquire+0x1d5/0x580 [ 43.463023] ? lock_acquire+0x1d5/0x580 [ 43.466961] ? lock_timer_base+0x1a3/0x2b0 [ 43.471165] ? find_held_lock+0x35/0x1d0 [ 43.475207] ? sock_def_wakeup+0x1f9/0x350 [ 43.479416] ? lock_downgrade+0x990/0x990 [ 43.483556] ? lock_release+0xa40/0xa40 [ 43.487505] sctp_outq_free+0x15/0x20 [ 43.491285] sctp_association_free+0x2d0/0x930 [ 43.495838] ? sctp_asconf_queue_teardown+0x700/0x700 [ 43.501184] ? sock_def_wakeup+0x222/0x350 [ 43.505385] ? sk_dst_check+0x560/0x560 [ 43.509327] ? sctp_association_put+0x74/0x2f0 [ 43.513876] ? sctp_association_hold+0x20/0x20 [ 43.518428] ? sctp_sm_lookup_event+0x95/0x3c0 [ 43.522980] sctp_do_sm+0x28e7/0x6d90 [ 43.526760] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 43.532783] ? do_raw_spin_trylock+0x190/0x190 [ 43.537333] ? print_usage_bug+0x480/0x480 [ 43.541535] ? print_usage_bug+0x480/0x480 [ 43.545736] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 43.550902] ? find_held_lock+0x35/0x1d0 [ 43.554934] ? skb_dequeue+0x12a/0x180 [ 43.558786] ? lock_downgrade+0x990/0x990 [ 43.562904] ? do_raw_spin_trylock+0x190/0x190 [ 43.567461] ? mark_held_locks+0xaf/0x100 [ 43.571591] ? trace_hardirqs_on+0xd/0x10 [ 43.575720] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 43.580274] sctp_close+0x3c6/0x980 [ 43.583876] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 43.589127] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.594110] ? trace_hardirqs_on+0xd/0x10 [ 43.598239] ? rcu_idle_enter+0x1a0/0x1a0 [ 43.602375] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 43.606839] ? ipv6_sock_mc_close+0x148/0x1a0 [ 43.611300] ? ipv6_sock_ac_drop+0x580/0x580 [ 43.615674] ? ip_mc_drop_socket+0x1ce/0x230 [ 43.620045] ? __fsnotify_parent+0xb4/0x3a0 [ 43.624335] inet_release+0xed/0x1c0 [ 43.628032] inet6_release+0x50/0x70 [ 43.631713] sock_release+0x8d/0x1e0 [ 43.635394] ? sock_release+0x1e0/0x1e0 [ 43.639344] sock_close+0x16/0x20 [ 43.642761] __fput+0x327/0x7e0 [ 43.646011] ? fput+0x140/0x140 [ 43.649262] ? check_same_owner+0x320/0x320 [ 43.653555] ____fput+0x15/0x20 [ 43.656803] task_work_run+0x18a/0x260 [ 43.660657] ? task_work_cancel+0x210/0x210 [ 43.664939] ? free_nsproxy+0x185/0x1f0 [ 43.668877] ? switch_task_namespaces+0xa2/0xc0 [ 43.673515] do_exit+0xa3a/0x1b10 [ 43.676936] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 43.682094] ? print_usage_bug+0x480/0x480 [ 43.686298] ? mm_update_next_owner+0x930/0x930 [ 43.690930] ? check_noncircular+0x20/0x20 [ 43.695128] ? check_noncircular+0x20/0x20 [ 43.699335] ? find_held_lock+0x35/0x1d0 [ 43.703372] ? find_held_lock+0x35/0x1d0 [ 43.707400] ? check_noncircular+0x20/0x20 [ 43.711601] ? check_noncircular+0x20/0x20 [ 43.715811] ? lock_downgrade+0x990/0x990 [ 43.719928] ? do_raw_spin_trylock+0x190/0x190 [ 43.724478] ? reacquire_held_locks+0x1fd/0x3d0 [ 43.729109] ? mark_held_locks+0xaf/0x100 [ 43.733218] ? reacquire_held_locks+0x1fd/0x3d0 [ 43.737855] ? check_noncircular+0x20/0x20 [ 43.742055] ? find_held_lock+0x35/0x1d0 [ 43.746098] ? release_sock+0x1d4/0x2a0 [ 43.750034] ? lock_downgrade+0x990/0x990 [ 43.754146] ? lock_downgrade+0x990/0x990 [ 43.758262] ? find_held_lock+0x35/0x1d0 [ 43.762294] ? get_signal+0x855/0x17e0 [ 43.766148] ? lock_downgrade+0x990/0x990 [ 43.770266] do_group_exit+0x149/0x400 [ 43.774119] ? __lock_is_held+0xb6/0x140 [ 43.778143] ? SyS_exit+0x30/0x30 [ 43.781584] ? _raw_spin_unlock_irq+0x27/0x70 [ 43.786044] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.791025] get_signal+0x7e8/0x17e0 [ 43.794723] ? ptrace_notify+0x130/0x130 [ 43.798756] ? inet_autobind+0x1f/0x180 [ 43.802694] ? __local_bh_enable_ip+0x9d/0x160 [ 43.807241] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.812220] ? release_sock+0x1d4/0x2a0 [ 43.816156] ? trace_hardirqs_on+0xd/0x10 [ 43.820267] ? __local_bh_enable_ip+0x9d/0x160 [ 43.824814] ? _raw_spin_unlock_bh+0x30/0x40 [ 43.829188] ? release_sock+0x1d4/0x2a0 [ 43.833126] ? __release_sock+0x360/0x360 [ 43.837240] ? trace_hardirqs_on+0xd/0x10 [ 43.841367] do_signal+0x94/0x1ee0 [ 43.844876] ? inet_sendmsg+0x11f/0x5e0 [ 43.848814] ? inet_sendmsg+0x126/0x5e0 [ 43.852752] ? __might_sleep+0x95/0x190 [ 43.856691] ? setup_sigcontext+0x7d0/0x7d0 [ 43.860974] ? selinux_socket_sendmsg+0x36/0x40 [ 43.865606] ? security_socket_sendmsg+0x89/0xb0 [ 43.870337] ? inet_recvmsg+0x5f0/0x5f0 [ 43.874280] ? sock_sendmsg+0x4f/0x110 [ 43.878134] ? fput+0xd2/0x140 [ 43.881294] ? SYSC_sendto+0x40d/0x5a0 [ 43.885153] ? SYSC_connect+0x470/0x470 [ 43.889094] ? find_held_lock+0x35/0x1d0 [ 43.893124] ? exit_to_usermode_loop+0x98/0x300 [ 43.897767] exit_to_usermode_loop+0x224/0x300 [ 43.902320] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 43.907829] ? handle_mm_fault+0x4a2/0x860 [ 43.912043] ? down_read_trylock+0xdb/0x170 [ 43.916335] syscall_return_slowpath+0x3a7/0x450 [ 43.921056] ? prepare_exit_to_usermode+0x220/0x220 [ 43.926035] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 43.930939] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.935918] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 43.940646] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 43.945365] RIP: 0033:0x445dd9 [ 43.948524] RSP: 002b:00007f4319011db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 43.956195] RAX: 0000000000000005 RBX: 0000000000000000 RCX: 0000000000445dd9 [ 43.963442] RDX: 0000000000000005 RSI: 0000000020fe7000 RDI: 0000000000000003 [ 43.970677] RBP: 0000000000000000 R08: 0000000020fe7ff0 R09: 0000000000000010 [ 43.977917] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 [ 43.985149] R13: 00000000007efe8f R14: 00007f43190129c0 R15: 0000000000000000 [ 43.992514] Dumping ftrace buffer: [ 43.996065] (ftrace buffer empty) [ 43.999745] Kernel Offset: disabled [ 44.003346] Rebooting in 86400 seconds..