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-1,10.128.0.25' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 106.591261] refcount_t: underflow; use-after-free. [ 106.592241] ------------[ cut here ]------------ [ 106.592928] WARNING: CPU: 0 PID: 2928 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 106.594207] Kernel panic - not syncing: panic_on_warn set ... [ 106.594207] [ 106.595265] CPU: 0 PID: 2928 Comm: syzkaller309001 Not tainted 4.13.0-rc4+ #30 [ 106.596252] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 106.597537] Call Trace: [ 106.597898] dump_stack+0x194/0x257 [ 106.598390] ? arch_local_irq_restore+0x53/0x53 [ 106.599023] panic+0x1e4/0x417 [ 106.599500] ? __warn+0x1d9/0x1d9 [ 106.599966] ? show_regs_print_info+0x65/0x65 [ 106.600578] ? refcount_sub_and_test+0x167/0x1b0 [ 106.601213] __warn+0x1c4/0x1d9 [ 106.601655] ? refcount_sub_and_test+0x167/0x1b0 [ 106.602302] report_bug+0x211/0x2d0 [ 106.602798] fixup_bug+0x40/0x90 [ 106.603254] do_trap+0x260/0x390 [ 106.603725] do_error_trap+0x120/0x390 [ 106.604245] ? vprintk_emit+0x49b/0x590 [ 106.604841] ? do_trap+0x390/0x390 [ 106.605318] ? refcount_sub_and_test+0x167/0x1b0 [ 106.606008] ? vprintk_emit+0x3ea/0x590 [ 106.606559] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 106.607269] do_invalid_op+0x1b/0x20 [ 106.607770] invalid_op+0x1e/0x30 [ 106.608237] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 106.609022] RSP: 0018:ffff8801d1e06ce8 EFLAGS: 00010286 [ 106.609784] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 106.610826] RDX: 0000000000000026 RSI: 1ffff1003a3c0d5d RDI: ffffed003a3c0d91 [ 106.614081] RBP: ffff8801d1e06d78 R08: 0000000000000001 R09: 0000000000000000 [ 106.621317] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a3c0d9e [ 106.628553] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d1f7527c [ 106.635812] ? refcount_sub_and_test+0x167/0x1b0 [ 106.640536] ? refcount_inc+0x50/0x50 [ 106.644303] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 106.649029] ? sctp_association_free+0x2d0/0x930 [ 106.653751] ? sctp_do_sm+0x28e7/0x6d90 [ 106.657692] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 106.662413] ? sctp_close+0x3c6/0x980 [ 106.666186] ? inet_release+0xed/0x1c0 [ 106.670045] sctp_wfree+0x183/0x620 [ 106.673642] ? __sctp_write_space+0x910/0x910 [ 106.678109] skb_release_head_state+0x124/0x200 [ 106.682746] skb_release_all+0x15/0x60 [ 106.686601] consume_skb+0x153/0x490 [ 106.690280] ? sctp_chunk_put+0x99/0x420 [ 106.694306] ? pskb_carve+0x1db0/0x1db0 [ 106.698247] ? sctp_chunk_hold+0x20/0x20 [ 106.702278] ? refcount_sub_and_test+0x115/0x1b0 [ 106.707001] ? refcount_inc+0x50/0x50 [ 106.710767] ? mark_held_locks+0xaf/0x100 [ 106.714882] ? sctp_datamsg_put+0x456/0x560 [ 106.719184] sctp_chunk_put+0x29c/0x420 [ 106.723127] ? sctp_chunk_hold+0x20/0x20 [ 106.727159] ? sctp_transport_dst_confirm+0x50/0x50 [ 106.732154] ? check_noncircular+0x20/0x20 [ 106.736356] ? check_noncircular+0x20/0x20 [ 106.740557] ? check_noncircular+0x20/0x20 [ 106.744770] sctp_chunk_free+0x53/0x60 [ 106.748629] __sctp_outq_teardown+0xc7d/0x15a0 [ 106.753198] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 106.758107] ? try_to_wake_up+0xf9/0x1600 [ 106.762224] ? lock_downgrade+0x990/0x990 [ 106.766339] ? lock_downgrade+0x990/0x990 [ 106.770470] ? do_raw_spin_trylock+0x190/0x190 [ 106.775017] ? do_raw_spin_trylock+0x190/0x190 [ 106.779580] ? trace_hardirqs_off+0xd/0x10 [ 106.783782] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 106.788852] ? try_to_wake_up+0xf9/0x1600 [ 106.792971] ? check_noncircular+0x20/0x20 [ 106.797176] ? migrate_swap_stop+0x970/0x970 [ 106.801550] ? save_stack_trace+0x16/0x20 [ 106.805675] ? save_trace+0x11f/0x350 [ 106.809445] ? print_usage_bug+0x480/0x480 [ 106.813655] ? lock_acquire+0x1d5/0x580 [ 106.817594] ? lock_acquire+0x1d5/0x580 [ 106.821536] ? lock_timer_base+0x1a3/0x2b0 [ 106.825741] ? find_held_lock+0x35/0x1d0 [ 106.829776] ? sock_def_wakeup+0x1f9/0x350 [ 106.833978] ? lock_downgrade+0x990/0x990 [ 106.838105] ? find_held_lock+0x35/0x1d0 [ 106.842133] ? lock_release+0xa40/0xa40 [ 106.846092] sctp_outq_free+0x15/0x20 [ 106.849861] sctp_association_free+0x2d0/0x930 [ 106.854431] ? sctp_asconf_queue_teardown+0x700/0x700 [ 106.859588] ? sock_def_wakeup+0x222/0x350 [ 106.863789] ? sk_dst_check+0x560/0x560 [ 106.867739] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 106.872731] ? trace_hardirqs_on+0xd/0x10 [ 106.876849] ? __wake_up+0x3f/0x50 [ 106.880360] sctp_do_sm+0x28e7/0x6d90 [ 106.884128] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 106.889294] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 106.895320] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 106.900481] ? print_usage_bug+0x480/0x480 [ 106.904686] ? print_usage_bug+0x480/0x480 [ 106.908894] ? update_load_avg+0x2a10/0x2a10 [ 106.913277] ? find_held_lock+0x35/0x1d0 [ 106.917314] ? skb_dequeue+0x12a/0x180 [ 106.921170] ? lock_downgrade+0x990/0x990 [ 106.925297] ? do_raw_spin_trylock+0x190/0x190 [ 106.929849] ? mark_held_locks+0xaf/0x100 [ 106.933979] ? trace_hardirqs_on+0xd/0x10 [ 106.938100] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 106.942653] sctp_close+0x3c6/0x980 [ 106.946431] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 106.951688] ? check_noncircular+0x20/0x20 [ 106.955886] ? lock_downgrade+0x990/0x990 [ 106.960001] ? lock_downgrade+0x990/0x990 [ 106.964119] ? do_raw_spin_trylock+0x190/0x190 [ 106.968677] ? locks_remove_file+0x414/0x560 [ 106.973057] ? fcntl_setlk+0x10c0/0x10c0 [ 106.977095] ? __fsnotify_parent+0xb4/0x3a0 [ 106.981387] ? ip_mc_drop_socket+0x1ce/0x230 [ 106.985767] inet_release+0xed/0x1c0 [ 106.989451] sock_release+0x8d/0x1e0 [ 106.993135] ? sock_release+0x1e0/0x1e0 [ 106.997074] sock_close+0x16/0x20 [ 107.000494] __fput+0x327/0x7e0 [ 107.003747] ? fput+0x140/0x140 [ 107.006996] ? alloc_fdtable+0x280/0x280 [ 107.011026] ? cpumask_weight.constprop.3+0x45/0x45 [ 107.016019] ____fput+0x15/0x20 [ 107.019269] task_work_run+0x18a/0x260 [ 107.023127] ? task_work_cancel+0x210/0x210 [ 107.027426] ? exit_to_usermode_loop+0x98/0x2d0 [ 107.032070] exit_to_usermode_loop+0x26d/0x2d0 [ 107.036628] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 107.042137] ? __do_page_fault+0x2b8/0xb60 [ 107.046345] syscall_return_slowpath+0x3a7/0x450 [ 107.051071] ? prepare_exit_to_usermode+0x220/0x220 [ 107.056062] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 107.060961] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 107.065948] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 107.070695] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 107.075679] RIP: 0033:0x445d39 [ 107.078837] RSP: 002b:00007fc6eaca6dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002b [ 107.086511] RAX: ffffffffffffff99 RBX: 0000000000000000 RCX: 0000000000445d39 [ 107.093749] RDX: 0000000020ffd000 RSI: 0000000020ffc000 RDI: 0000000000000003 [ 107.100990] RBP: 0000000000000000 R08: 00007fc6eaca7700 R09: 00007fc6eaca7700 [ 107.108227] R10: 00007fc6eaca7700 R11: 0000000000000202 R12: 0000000000000000 [ 107.115466] R13: 00007ffd1cda53bf R14: 00007fc6eaca79c0 R15: 0000000000000000 [ 107.123168] Dumping ftrace buffer: [ 107.126734] (ftrace buffer empty) [ 107.130423] Kernel Offset: disabled [ 107.134023] Rebooting in 86400 seconds..