serialport: Connected to syzkaller.us-central1-c.ci-upstream-kasan-gce-3 port 1 (session ID: bef3192e0af14c54fa0656093af4466433468bb6930bcd4e70f0eac159f8a413, active connections: 1). 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-3,10.128.0.21' (ECDSA) to the list of known hosts. 2017/08/04 00:26:59 parsed 1 programs 2017/08/04 00:26:59 executed programs: 0 syzkaller login: [ 51.732592] refcount_t: underflow; use-after-free. [ 51.733507] ------------[ cut here ]------------ [ 51.734365] WARNING: CPU: 1 PID: 2933 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 51.735525] Kernel panic - not syncing: panic_on_warn set ... [ 51.735525] [ 51.736507] CPU: 1 PID: 2933 Comm: syz-executor0 Not tainted 4.13.0-rc3+ #17 [ 51.737522] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.738790] Call Trace: [ 51.739179] dump_stack+0x194/0x257 [ 51.739689] ? arch_local_irq_restore+0x53/0x53 [ 51.740326] panic+0x1e4/0x417 [ 51.740778] ? __warn+0x1d9/0x1d9 [ 51.741250] ? show_regs_print_info+0x65/0x65 [ 51.741928] ? refcount_sub_and_test+0x167/0x1b0 [ 51.742596] __warn+0x1c4/0x1d9 [ 51.743065] ? refcount_sub_and_test+0x167/0x1b0 [ 51.743702] report_bug+0x211/0x2d0 [ 51.744214] fixup_bug+0x40/0x90 [ 51.744672] do_trap+0x260/0x390 [ 51.745137] do_error_trap+0x120/0x390 [ 51.745664] ? do_trap+0x390/0x390 [ 51.746142] ? refcount_sub_and_test+0x167/0x1b0 [ 51.746776] ? vprintk_emit+0x3ea/0x590 [ 51.747324] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 51.747975] do_invalid_op+0x1b/0x20 [ 51.748567] invalid_op+0x1e/0x30 [ 51.749055] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 51.749769] RSP: 0018:ffff8801d19b6330 EFLAGS: 00010286 [ 51.750507] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 51.751486] RDX: 0000000000000026 RSI: 1ffff1003a336c26 RDI: ffffed003a336c5a [ 51.752464] RBP: ffff8801d19b63c0 R08: 0000000000000001 R09: 0000000000000000 [ 51.757906] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a336c67 [ 51.765145] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801da9b327c [ 51.772410] ? refcount_inc+0x50/0x50 [ 51.776180] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 51.780905] ? sctp_association_free+0x2d0/0x930 [ 51.785625] ? sctp_do_sm+0x28e7/0x6d90 [ 51.789574] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 51.794296] ? sctp_close+0x3c6/0x980 [ 51.798066] ? inet_release+0xed/0x1c0 [ 51.801924] sctp_wfree+0x183/0x620 [ 51.805519] ? __sctp_write_space+0x910/0x910 [ 51.809991] skb_release_head_state+0x124/0x200 [ 51.814630] skb_release_all+0x15/0x60 [ 51.818484] consume_skb+0x153/0x490 [ 51.822163] ? sctp_chunk_put+0x99/0x420 [ 51.826189] ? pskb_carve+0x1db0/0x1db0 [ 51.830127] ? sctp_chunk_hold+0x20/0x20 [ 51.834162] ? refcount_sub_and_test+0x115/0x1b0 [ 51.838887] ? refcount_inc+0x50/0x50 [ 51.842655] ? mark_held_locks+0xaf/0x100 [ 51.846777] ? sctp_datamsg_put+0x456/0x560 [ 51.851076] sctp_chunk_put+0x29c/0x420 [ 51.855021] ? sctp_chunk_hold+0x20/0x20 [ 51.859058] ? sctp_transport_dst_confirm+0x50/0x50 [ 51.864056] ? noop_count+0x40/0x40 [ 51.867659] sctp_chunk_free+0x53/0x60 [ 51.871515] __sctp_outq_teardown+0xc7d/0x15a0 [ 51.876074] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 51.880974] ? lock_downgrade+0x990/0x990 [ 51.885093] ? lock_release+0xa40/0xa40 [ 51.889037] ? __free_insn_slot+0x5c0/0x5c0 [ 51.893331] ? update_stack_state+0x700/0x700 [ 51.897794] ? print_usage_bug+0x480/0x480 [ 51.902004] ? is_bpf_text_address+0xa4/0x120 [ 51.906468] ? __kernel_text_address+0xae/0xe0 [ 51.911018] ? unwind_get_return_address+0x61/0xa0 [ 51.915919] ? __save_stack_trace+0x7e/0xd0 [ 51.920214] ? check_noncircular+0x20/0x20 [ 51.924416] ? print_usage_bug+0x480/0x480 [ 51.928617] ? SOFTIRQ_verbose+0x10/0x10 [ 51.932645] ? save_stack_trace+0x16/0x20 [ 51.936762] ? save_trace+0x11f/0x350 [ 51.940540] ? lock_acquire+0x1d5/0x580 [ 51.944479] ? lock_acquire+0x1d5/0x580 [ 51.948420] ? lock_timer_base+0x1a3/0x2b0 [ 51.952625] ? find_held_lock+0x35/0x1d0 [ 51.956664] ? sock_def_wakeup+0x1f9/0x350 [ 51.960867] ? lock_downgrade+0x990/0x990 [ 51.964988] ? lock_release+0xa40/0xa40 [ 51.968940] sctp_outq_free+0x15/0x20 [ 51.972715] sctp_association_free+0x2d0/0x930 [ 51.977270] ? sctp_asconf_queue_teardown+0x700/0x700 [ 51.982433] ? sock_def_wakeup+0x222/0x350 [ 51.986636] ? sk_dst_check+0x560/0x560 [ 51.990579] ? sctp_association_put+0x74/0x2f0 [ 51.995129] ? sctp_association_hold+0x20/0x20 [ 51.999682] ? unwind_get_return_address+0x61/0xa0 [ 52.004580] ? print_usage_bug+0x480/0x480 [ 52.008787] ? sctp_sm_lookup_event+0x95/0x3c0 [ 52.013344] sctp_do_sm+0x28e7/0x6d90 [ 52.017126] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 52.023155] ? get_signal+0x7e8/0x17e0 [ 52.027015] ? print_usage_bug+0x480/0x480 [ 52.031233] ? check_noncircular+0x20/0x20 [ 52.035439] ? print_usage_bug+0x480/0x480 [ 52.039661] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 52.044843] ? find_held_lock+0x35/0x1d0 [ 52.048879] ? skb_dequeue+0x12a/0x180 [ 52.052734] ? lock_downgrade+0x990/0x990 [ 52.056854] ? do_raw_spin_trylock+0x190/0x190 [ 52.061406] ? mark_held_locks+0xaf/0x100 [ 52.065528] ? trace_hardirqs_on+0xd/0x10 [ 52.069653] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 52.074216] sctp_close+0x3c6/0x980 [ 52.077821] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 52.083064] ? trace_hardirqs_off+0xd/0x10 [ 52.087266] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 52.092339] ? depot_save_stack+0x3b5/0x490 [ 52.096637] ? locks_remove_file+0x414/0x560 [ 52.101021] ? fcntl_setlk+0x10c0/0x10c0 [ 52.105046] ? free_fs_struct+0x4f/0x60 [ 52.108993] ? __fsnotify_parent+0xb4/0x3a0 [ 52.113283] ? ip_mc_drop_socket+0x1ce/0x230 [ 52.117663] inet_release+0xed/0x1c0 [ 52.121346] sock_release+0x8d/0x1e0 [ 52.125027] ? sock_release+0x1e0/0x1e0 [ 52.128977] sock_close+0x16/0x20 [ 52.132403] __fput+0x327/0x7e0 [ 52.135657] ? fput+0x140/0x140 [ 52.138921] ? do_raw_spin_trylock+0x190/0x190 [ 52.143475] ? check_same_owner+0x320/0x320 [ 52.147774] ____fput+0x15/0x20 [ 52.151036] task_work_run+0x18a/0x260 [ 52.154894] ? task_work_cancel+0x210/0x210 [ 52.159187] ? _raw_spin_unlock+0x22/0x30 [ 52.163309] ? switch_task_namespaces+0x87/0xc0 [ 52.167956] do_exit+0xa32/0x1b10 [ 52.171378] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 52.176540] ? print_usage_bug+0x480/0x480 [ 52.180756] ? prepare_to_wait_exclusive+0x192/0x530 [ 52.185834] ? lock_downgrade+0x8b1/0x990 [ 52.189951] ? exit_notify+0xb10/0xb10 [ 52.193811] ? do_raw_spin_trylock+0x190/0x190 [ 52.198376] ? find_held_lock+0x35/0x1d0 [ 52.202411] ? find_held_lock+0x35/0x1d0 [ 52.206449] ? check_noncircular+0x20/0x20 [ 52.210650] ? check_noncircular+0x20/0x20 [ 52.214865] ? lock_downgrade+0x990/0x990 [ 52.218986] ? do_raw_spin_trylock+0x190/0x190 [ 52.223542] ? reacquire_held_locks+0x1fd/0x3d0 [ 52.228177] ? mark_held_locks+0xaf/0x100 [ 52.232291] ? reacquire_held_locks+0x1fd/0x3d0 [ 52.236932] ? check_noncircular+0x20/0x20 [ 52.241135] ? find_held_lock+0x35/0x1d0 [ 52.245172] ? release_sock+0x1d4/0x2a0 [ 52.249116] ? lock_downgrade+0x990/0x990 [ 52.253231] ? lock_downgrade+0x990/0x990 [ 52.257354] ? find_held_lock+0x35/0x1d0 [ 52.261400] ? get_signal+0x855/0x17e0 [ 52.265254] ? lock_downgrade+0x990/0x990 [ 52.269377] do_group_exit+0x149/0x400 [ 52.273243] ? __lock_is_held+0xb6/0x140 [ 52.277272] ? SyS_exit+0x30/0x30 [ 52.280694] ? _raw_spin_unlock_irq+0x27/0x70 [ 52.285156] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 52.290151] get_signal+0x7e8/0x17e0 [ 52.293860] ? ptrace_notify+0x130/0x130 [ 52.298786] ? __fget+0x333/0x570 [ 52.302216] ? find_held_lock+0x35/0x1d0 [ 52.306255] ? __might_fault+0x110/0x1d0 [ 52.310304] ? selinux_tun_dev_create+0xc0/0xc0 [ 52.314963] do_signal+0x94/0x1ee0 [ 52.318477] ? inet_sendmsg+0x11f/0x5e0 [ 52.322418] ? inet_sendmsg+0x126/0x5e0 [ 52.326364] ? __might_sleep+0x95/0x190 [ 52.330328] ? setup_sigcontext+0x7d0/0x7d0 [ 52.334618] ? selinux_socket_sendmsg+0x36/0x40 [ 52.339254] ? security_socket_sendmsg+0x89/0xb0 [ 52.343979] ? inet_recvmsg+0x5f0/0x5f0 [ 52.347924] ? sock_sendmsg+0x4f/0x110 [ 52.351786] ? fput+0xd2/0x140 [ 52.354947] ? SYSC_sendto+0x40d/0x5a0 [ 52.358804] ? SYSC_connect+0x470/0x470 [ 52.362748] ? fget_raw+0x20/0x20 [ 52.366168] ? __release_sock+0x360/0x360 [ 52.370286] ? exit_to_usermode_loop+0x98/0x2d0 [ 52.374929] exit_to_usermode_loop+0x21c/0x2d0 [ 52.379481] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 52.385015] syscall_return_slowpath+0x3a7/0x450 [ 52.389746] ? prepare_exit_to_usermode+0x220/0x220 [ 52.394736] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 52.399634] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 52.404628] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 52.409358] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 52.414081] RIP: 0033:0x4512c9 [ 52.417239] RSP: 002b:00007f711de14c08 EFLAGS: 00000216 ORIG_RAX: 000000000000002c [ 52.424913] RAX: 000000000000001a RBX: 0000000000718150 RCX: 00000000004512c9 [ 52.432151] RDX: 000000000000001a RSI: 0000000020001f98 RDI: 0000000000000003 [ 52.439387] RBP: 00000000000047b0 R08: 0000000020001ff0 R09: 0000000000000010 [ 52.446633] R10: 0000000000000004 R11: 0000000000000216 R12: 00000000004ba082 [ 52.453871] R13: 00000000ffffffff R14: 0000000000000003 R15: 0000000020001f98 [ 52.461656] Dumping ftrace buffer: [ 52.465228] (ftrace buffer empty) [ 52.468909] Kernel Offset: disabled [ 52.472510] Rebooting in 86400 seconds..