[info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[ 8.421611] rsyslogd (2863) used greatest stack depth: 14592 bytes left [?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-mmots-kasan-gce-8,10.128.0.14' (ECDSA) to the list of known hosts. 2017/10/24 03:07:56 parsed 1 programs 2017/10/24 03:07:56 executed programs: 0 2017/10/24 03:08:01 executed programs: 591 2017/10/24 03:08:06 executed programs: 1185 syzkaller login: [ 70.189564] refcount_t: underflow; use-after-free. [ 70.190715] ------------[ cut here ]------------ [ 70.191611] WARNING: CPU: 1 PID: 8943 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 70.193167] Kernel panic - not syncing: panic_on_warn set ... [ 70.193167] [ 70.194209] CPU: 1 PID: 8943 Comm: syz-executor3 Not tainted 4.14.0-rc5-mm1+ #20 [ 70.195219] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 70.196439] Call Trace: [ 70.196805] dump_stack+0x194/0x257 [ 70.197300] ? arch_local_irq_restore+0x53/0x53 [ 70.197929] ? vsnprintf+0x1ed/0x1900 [ 70.198447] panic+0x1e4/0x41c [ 70.198890] ? refcount_error_report+0x214/0x214 [ 70.199531] ? show_regs_print_info+0x65/0x65 [ 70.200200] ? __warn+0x1a9/0x1e0 [ 70.200673] ? refcount_sub_and_test+0x167/0x1b0 [ 70.201305] __warn+0x1c4/0x1e0 [ 70.201750] ? refcount_sub_and_test+0x167/0x1b0 [ 70.202387] report_bug+0x211/0x2d0 [ 70.202901] fixup_bug+0x40/0x90 [ 70.203361] do_trap+0x260/0x390 [ 70.203824] do_error_trap+0x120/0x390 [ 70.204359] ? do_trap+0x390/0x390 [ 70.204850] ? refcount_sub_and_test+0x167/0x1b0 [ 70.205494] ? vprintk_emit+0x3ea/0x590 [ 70.206063] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 70.206734] do_invalid_op+0x1b/0x20 [ 70.207235] invalid_op+0x18/0x20 [ 70.207704] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 70.208426] RSP: 0018:ffff8801c261e500 EFLAGS: 00010282 [ 70.209139] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 70.213099] RDX: 0000000000000026 RSI: 1ffff100384c3c60 RDI: ffffed00384c3c94 [ 70.220339] RBP: ffff8801c261e590 R08: 0000000000000001 R09: 0000000000000000 [ 70.227586] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff100384c3ca1 [ 70.234839] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801cfb162bc [ 70.242125] ? refcount_inc+0x50/0x50 [ 70.245913] ? sctp_outq_free+0x15/0x20 [ 70.249875] ? sctp_do_sm+0x271b/0x6a30 [ 70.253835] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 70.258568] ? sctp_close+0x3c6/0x980 [ 70.262338] ? inet_release+0xed/0x1c0 [ 70.266194] ? sock_release+0x8d/0x1e0 [ 70.270060] sctp_wfree+0x183/0x620 [ 70.273658] ? __sctp_write_space+0x910/0x910 [ 70.278137] skb_release_head_state+0x124/0x200 [ 70.282778] skb_release_all+0x15/0x60 [ 70.286634] consume_skb+0x153/0x490 [ 70.290317] ? sctp_chunk_put+0x99/0x420 [ 70.294346] ? alloc_skb_with_frags+0x750/0x750 [ 70.298984] ? sctp_chunk_hold+0x20/0x20 [ 70.303021] ? refcount_sub_and_test+0x115/0x1b0 [ 70.307746] ? refcount_inc+0x50/0x50 [ 70.311514] ? mark_held_locks+0xaf/0x100 [ 70.315636] ? sctp_datamsg_put+0x456/0x560 [ 70.319933] sctp_chunk_put+0x29c/0x420 [ 70.323877] ? sctp_chunk_hold+0x20/0x20 [ 70.327912] ? sctp_transport_dst_confirm+0x50/0x50 [ 70.332900] ? sctp_sched_fcfs_dequeue+0x198/0x290 [ 70.337798] ? sctp_sched_dequeue_common+0x5d0/0x5d0 [ 70.342867] ? print_irqtrace_events+0x270/0x270 [ 70.347597] ? print_irqtrace_events+0x270/0x270 [ 70.352324] sctp_chunk_free+0x53/0x60 [ 70.356180] __sctp_outq_teardown+0xa5b/0x1230 [ 70.360733] ? __page_frag_cache_drain+0x1c0/0x1c0 [ 70.365640] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 70.370539] ? print_irqtrace_events+0x270/0x270 [ 70.375263] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 70.380431] ? __lock_acquire+0x6aa/0x3d50 [ 70.384635] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 70.389626] ? check_noncircular+0x20/0x20 [ 70.393833] ? print_irqtrace_events+0x270/0x270 [ 70.398556] ? __lock_acquire+0x6aa/0x3d50 [ 70.402766] ? lock_acquire+0x1d5/0x580 [ 70.406707] ? lock_acquire+0x1d5/0x580 [ 70.410651] ? lock_timer_base+0x1a3/0x2b0 [ 70.414857] ? find_held_lock+0x35/0x1d0 [ 70.418895] ? sock_def_wakeup+0x1f9/0x350 [ 70.423099] ? lock_downgrade+0x990/0x990 [ 70.427218] ? lock_release+0xa40/0xa40 [ 70.431167] sctp_outq_free+0x15/0x20 [ 70.434939] sctp_association_free+0x2d0/0x930 [ 70.439495] ? sctp_asconf_queue_teardown+0x700/0x700 [ 70.444652] ? sock_def_wakeup+0x222/0x350 [ 70.448855] ? sk_dst_check+0x560/0x560 [ 70.452800] ? sctp_association_put+0x74/0x2f0 [ 70.457349] ? sctp_association_hold+0x20/0x20 [ 70.461901] ? check_noncircular+0x20/0x20 [ 70.466111] sctp_do_sm+0x271b/0x6a30 [ 70.469896] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 70.475927] ? print_irqtrace_events+0x270/0x270 [ 70.480647] ? __lock_acquire+0x6aa/0x3d50 [ 70.484847] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 70.490000] ? __lock_acquire+0x6aa/0x3d50 [ 70.494208] ? print_irqtrace_events+0x270/0x270 [ 70.498945] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 70.504105] ? find_held_lock+0x35/0x1d0 [ 70.508144] ? skb_dequeue+0x12a/0x180 [ 70.512000] ? lock_downgrade+0x990/0x990 [ 70.516126] ? do_raw_spin_trylock+0x190/0x190 [ 70.520680] ? mark_held_locks+0xaf/0x100 [ 70.524803] ? trace_hardirqs_on+0xd/0x10 [ 70.528927] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 70.533483] sctp_close+0x3c6/0x980 [ 70.537076] ? is_bpf_text_address+0xa4/0x120 [ 70.541551] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 70.546797] ? __save_stack_trace+0x7e/0xd0 [ 70.551088] ? check_noncircular+0x20/0x20 [ 70.555292] ? depot_save_stack+0x12c/0x490 [ 70.559590] ? locks_remove_file+0x3fa/0x5a0 [ 70.563982] ? fcntl_setlk+0x10c0/0x10c0 [ 70.568015] ? free_fs_struct+0x4f/0x60 [ 70.571962] ? __fsnotify_parent+0xb4/0x3a0 [ 70.576253] ? ip_mc_drop_socket+0x1ce/0x230 [ 70.580653] inet_release+0xed/0x1c0 [ 70.584346] sock_release+0x8d/0x1e0 [ 70.588031] ? sock_release+0x1e0/0x1e0 [ 70.591973] sock_close+0x16/0x20 [ 70.595397] __fput+0x327/0x7e0 [ 70.598652] ? fput+0x140/0x140 [ 70.601903] ? _raw_spin_unlock_irq+0x27/0x70 [ 70.606373] ____fput+0x15/0x20 [ 70.609623] task_work_run+0x199/0x270 [ 70.613484] ? task_work_cancel+0x210/0x210 [ 70.617773] ? _raw_spin_unlock+0x22/0x30 [ 70.621892] ? switch_task_namespaces+0x87/0xc0 [ 70.626536] do_exit+0x9b5/0x1ad0 [ 70.629969] ? mm_update_next_owner+0x930/0x930 [ 70.634611] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 70.640469] ? rcu_note_context_switch+0x710/0x710 [ 70.645540] ? futex_wait_setup+0x14a/0x3d0 [ 70.649833] ? __might_sleep+0x95/0x190 [ 70.653782] ? find_held_lock+0x35/0x1d0 [ 70.657821] ? futex_wait+0x402/0x990 [ 70.661594] ? lock_downgrade+0x990/0x990 [ 70.665717] ? do_raw_spin_trylock+0x190/0x190 [ 70.670267] ? check_noncircular+0x20/0x20 [ 70.674481] ? mmdrop+0x18/0x30 [ 70.677729] ? drop_futex_key_refs.isra.13+0x63/0xa0 [ 70.682886] ? futex_wait+0x69e/0x990 [ 70.686660] ? find_held_lock+0x35/0x1d0 [ 70.690698] ? get_signal+0x7ae/0x16d0 [ 70.694554] ? lock_downgrade+0x990/0x990 [ 70.698681] do_group_exit+0x149/0x400 [ 70.702540] ? __lock_is_held+0xb6/0x140 [ 70.706570] ? SyS_exit+0x30/0x30 [ 70.709992] ? _raw_spin_unlock_irq+0x27/0x70 [ 70.714460] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 70.719451] get_signal+0x73f/0x16d0 [ 70.723146] ? ptrace_notify+0x130/0x130 [ 70.727182] ? __schedule+0x8f3/0x2060 [ 70.731044] ? exit_robust_list+0x240/0x240 [ 70.735334] ? __sched_text_start+0x8/0x8 [ 70.739450] ? reacquire_held_locks+0x1fd/0x3d0 [ 70.744084] ? reacquire_held_locks+0x1fd/0x3d0 [ 70.748731] do_signal+0x94/0x1ee0 [ 70.752248] ? lock_downgrade+0x990/0x990 [ 70.756364] ? setup_sigcontext+0x7d0/0x7d0 [ 70.760655] ? do_raw_spin_trylock+0x190/0x190 [ 70.765203] ? lock_release+0xa40/0xa40 [ 70.769152] ? schedule+0xf5/0x430 [ 70.772665] ? __schedule+0x2060/0x2060 [ 70.776613] ? _raw_spin_unlock_bh+0x30/0x40 [ 70.780989] ? release_sock+0x1d4/0x2a0 [ 70.784934] ? sctp_hash_endpoint+0x275/0x320 [ 70.789396] ? __release_sock+0x360/0x360 [ 70.793517] ? exit_to_usermode_loop+0x8c/0x310 [ 70.798161] exit_to_usermode_loop+0x214/0x310 [ 70.802713] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 70.808216] ? sctp_transport_get_idx+0x70/0x70 [ 70.812865] syscall_return_slowpath+0x42f/0x510 [ 70.817591] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 70.822578] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 70.827477] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 70.832462] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 70.837196] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 70.841918] RIP: 0033:0x452869 [ 70.845077] RSP: 002b:00007f4277a68ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 70.852754] RAX: fffffffffffffe00 RBX: 0000000000758270 RCX: 0000000000452869 [ 70.859990] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000758270 [ 70.867233] RBP: 0000000000758270 R08: 0000000000000000 R09: 0000000000758248 [ 70.874468] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 70.881707] R13: 0000000000a6f7ff R14: 00007f4277a699c0 R15: 000000000000000c [ 70.889551] Dumping ftrace buffer: [ 70.893120] (ftrace buffer empty) [ 70.896798] Kernel Offset: disabled [ 70.900391] Rebooting in 86400 seconds..