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-next-kasan-gce-1,10.128.15.200' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 35.957423] refcount_t: underflow; use-after-free. [ 35.958252] ------------[ cut here ]------------ [ 35.958904] WARNING: CPU: 0 PID: 3038 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 35.960182] Kernel panic - not syncing: panic_on_warn set ... [ 35.960182] [ 35.961276] CPU: 0 PID: 3038 Comm: syzkaller367773 Not tainted 4.13.0-rc5-next-20170817+ #5 [ 35.962410] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.963629] Call Trace: [ 35.963988] dump_stack+0x194/0x257 [ 35.964514] ? arch_local_irq_restore+0x53/0x53 [ 35.965173] panic+0x1e4/0x417 [ 35.965621] ? __warn+0x1d9/0x1d9 [ 35.966087] ? show_regs_print_info+0x65/0x65 [ 35.966698] ? refcount_sub_and_test+0x167/0x1b0 [ 35.967331] __warn+0x1c4/0x1d9 [ 35.967773] ? refcount_sub_and_test+0x167/0x1b0 [ 35.968408] report_bug+0x211/0x2d0 [ 35.968900] fixup_bug+0x40/0x90 [ 35.969356] do_trap+0x260/0x390 [ 35.969887] do_error_trap+0x120/0x390 [ 35.970415] ? do_trap+0x390/0x390 [ 35.970892] ? refcount_sub_and_test+0x167/0x1b0 [ 35.971524] ? vprintk_emit+0x3ea/0x590 [ 35.972064] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 35.972714] do_invalid_op+0x1b/0x20 [ 35.973230] invalid_op+0x18/0x20 [ 35.973695] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 35.974403] RSP: 0018:ffff8801bf5e6320 EFLAGS: 00010286 [ 35.975131] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 35.976083] RDX: 0000000000000026 RSI: 1ffff10037ebcc24 RDI: ffffed0037ebcc58 [ 35.977033] RBP: ffff8801bf5e63b0 R08: 0000000000000001 R09: 0000000000000000 [ 35.981050] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10037ebcc65 [ 35.988289] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801bfbe527c [ 35.995558] ? refcount_inc+0x50/0x50 [ 35.999327] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 36.004052] ? sctp_association_free+0x2d0/0x930 [ 36.008774] ? sctp_do_sm+0x28e7/0x6d90 [ 36.012717] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 36.017440] ? sctp_close+0x3c6/0x980 [ 36.021208] ? inet_release+0xed/0x1c0 [ 36.025079] sctp_wfree+0x183/0x620 [ 36.028678] ? __sctp_write_space+0x910/0x910 [ 36.033145] skb_release_head_state+0x124/0x200 [ 36.037783] skb_release_all+0x15/0x60 [ 36.041639] consume_skb+0x153/0x490 [ 36.045318] ? sctp_chunk_put+0x99/0x420 [ 36.049347] ? alloc_skb_with_frags+0x710/0x710 [ 36.053986] ? sctp_chunk_hold+0x20/0x20 [ 36.058021] ? refcount_sub_and_test+0x115/0x1b0 [ 36.062747] ? refcount_inc+0x50/0x50 [ 36.066517] ? mark_held_locks+0xaf/0x100 [ 36.070639] ? sctp_datamsg_put+0x456/0x560 [ 36.074936] sctp_chunk_put+0x29c/0x420 [ 36.078884] ? sctp_chunk_hold+0x20/0x20 [ 36.082920] ? sctp_transport_dst_confirm+0x50/0x50 [ 36.087908] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 36.093066] ? lock_release+0xa40/0xa40 [ 36.097016] ? __read_once_size_nocheck.constprop.8+0x10/0x10 [ 36.102884] ? entry_SYSCALL_64_fastpath+0xbc/0xbe [ 36.107787] ? bpf_prog_kallsyms_find+0xbd/0x440 [ 36.112512] ? show_initstate+0xb0/0xb0 [ 36.116458] sctp_chunk_free+0x53/0x60 [ 36.120324] __sctp_outq_teardown+0xc7d/0x15a0 [ 36.124876] ? lock_downgrade+0x990/0x990 [ 36.128997] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 36.133895] ? unwind_dump+0x4c0/0x4c0 [ 36.137762] ? is_bpf_text_address+0xa4/0x120 [ 36.142228] ? __kernel_text_address+0xae/0xe0 [ 36.146777] ? unwind_get_return_address+0x61/0xa0 [ 36.151674] ? __save_stack_trace+0x7e/0xd0 [ 36.155971] ? add_lock_to_list.isra.35+0x1ff/0x4f0 [ 36.160961] ? SOFTIRQ_verbose+0x10/0x10 [ 36.164993] ? save_stack_trace+0x16/0x20 [ 36.169108] ? save_trace+0x11f/0x350 [ 36.172880] ? check_noncircular+0x20/0x20 [ 36.177084] ? print_usage_bug+0x480/0x480 [ 36.181296] ? lock_acquire+0x1d5/0x580 [ 36.185236] ? lock_acquire+0x1d5/0x580 [ 36.189175] ? lock_timer_base+0x1a3/0x2b0 [ 36.193383] ? find_held_lock+0x35/0x1d0 [ 36.197430] ? sock_def_wakeup+0x1f9/0x350 [ 36.201635] ? lock_downgrade+0x990/0x990 [ 36.205764] ? lock_release+0xa40/0xa40 [ 36.209714] sctp_outq_free+0x15/0x20 [ 36.213486] sctp_association_free+0x2d0/0x930 [ 36.218046] ? sctp_asconf_queue_teardown+0x700/0x700 [ 36.223211] ? sock_def_wakeup+0x222/0x350 [ 36.227416] ? sk_dst_check+0x560/0x560 [ 36.231360] ? sctp_association_put+0x74/0x2f0 [ 36.235909] ? sctp_association_hold+0x20/0x20 [ 36.240473] ? sctp_sm_lookup_event+0x95/0x3c0 [ 36.245026] sctp_do_sm+0x28e7/0x6d90 [ 36.248809] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 36.254842] ? print_usage_bug+0x480/0x480 [ 36.259048] ? print_usage_bug+0x480/0x480 [ 36.263257] ? depot_save_stack+0x3b5/0x490 [ 36.267554] ? find_held_lock+0x35/0x1d0 [ 36.271677] ? skb_dequeue+0x12a/0x180 [ 36.275533] ? lock_downgrade+0x990/0x990 [ 36.279654] ? do_raw_spin_trylock+0x190/0x190 [ 36.284207] ? mark_held_locks+0xaf/0x100 [ 36.288336] ? trace_hardirqs_on+0xd/0x10 [ 36.292459] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 36.297035] sctp_close+0x3c6/0x980 [ 36.300644] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 36.305893] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.310883] ? trace_hardirqs_on+0xd/0x10 [ 36.315012] ? rcu_eqs_enter_common.constprop.73+0x270/0x270 [ 36.320779] ? locks_remove_file+0x3fa/0x5a0 [ 36.325155] ? fcntl_setlk+0x10c0/0x10c0 [ 36.329182] ? find_held_lock+0x35/0x1d0 [ 36.333220] ? __fsnotify_parent+0xb4/0x3a0 [ 36.337509] ? ip_mc_drop_socket+0x1ce/0x230 [ 36.341896] inet_release+0xed/0x1c0 [ 36.345581] sock_release+0x8d/0x1e0 [ 36.349262] ? sock_release+0x1e0/0x1e0 [ 36.353201] sock_close+0x16/0x20 [ 36.356620] __fput+0x327/0x7e0 [ 36.359869] ? fput+0x140/0x140 [ 36.363123] ? check_same_owner+0x320/0x320 [ 36.367418] ____fput+0x15/0x20 [ 36.370664] task_work_run+0x199/0x270 [ 36.374522] ? task_work_cancel+0x210/0x210 [ 36.378813] ? free_nsproxy+0x185/0x1f0 [ 36.382760] ? switch_task_namespaces+0xa2/0xc0 [ 36.387400] do_exit+0xa52/0x1b30 [ 36.390829] ? print_usage_bug+0x480/0x480 [ 36.395046] ? mm_update_next_owner+0x930/0x930 [ 36.399683] ? check_noncircular+0x20/0x20 [ 36.403898] ? check_noncircular+0x20/0x20 [ 36.408114] ? find_held_lock+0x35/0x1d0 [ 36.412147] ? find_held_lock+0x35/0x1d0 [ 36.416179] ? check_noncircular+0x20/0x20 [ 36.420381] ? check_noncircular+0x20/0x20 [ 36.424584] ? lock_downgrade+0x990/0x990 [ 36.428705] ? do_raw_spin_trylock+0x190/0x190 [ 36.433258] ? reacquire_held_locks+0x1fd/0x3d0 [ 36.437891] ? mark_held_locks+0xaf/0x100 [ 36.442005] ? reacquire_held_locks+0x1fd/0x3d0 [ 36.446642] ? check_noncircular+0x20/0x20 [ 36.450845] ? find_held_lock+0x35/0x1d0 [ 36.454886] ? release_sock+0x1d4/0x2a0 [ 36.458832] ? lock_downgrade+0x990/0x990 [ 36.462949] ? lock_downgrade+0x990/0x990 [ 36.467079] ? find_held_lock+0x35/0x1d0 [ 36.471119] ? get_signal+0x855/0x17e0 [ 36.474975] ? lock_downgrade+0x990/0x990 [ 36.479098] do_group_exit+0x149/0x400 [ 36.482954] ? __lock_is_held+0xb6/0x140 [ 36.486981] ? SyS_exit+0x30/0x30 [ 36.490399] ? _raw_spin_unlock_irq+0x27/0x70 [ 36.494867] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.499858] get_signal+0x7e8/0x17e0 [ 36.503568] ? ptrace_notify+0x130/0x130 [ 36.507598] ? __local_bh_enable_ip+0x9d/0x160 [ 36.512149] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.517135] ? release_sock+0x1d4/0x2a0 [ 36.521077] ? trace_hardirqs_on+0xd/0x10 [ 36.525199] ? __local_bh_enable_ip+0x9d/0x160 [ 36.529750] ? _raw_spin_unlock_bh+0x30/0x40 [ 36.534124] ? release_sock+0x1d4/0x2a0 [ 36.538073] ? __release_sock+0x360/0x360 [ 36.542190] ? trace_hardirqs_on+0xd/0x10 [ 36.546309] do_signal+0x94/0x1ee0 [ 36.549822] ? inet_sendmsg+0x11f/0x5e0 [ 36.553763] ? inet_sendmsg+0x126/0x5e0 [ 36.557704] ? __might_sleep+0x95/0x190 [ 36.561654] ? setup_sigcontext+0x7d0/0x7d0 [ 36.565944] ? selinux_socket_sendmsg+0x36/0x40 [ 36.570577] ? security_socket_sendmsg+0x89/0xb0 [ 36.575301] ? inet_recvmsg+0x5f0/0x5f0 [ 36.579255] ? sock_sendmsg+0x4f/0x110 [ 36.583110] ? fput+0xd2/0x140 [ 36.586273] ? SYSC_sendto+0x40d/0x5a0 [ 36.590132] ? SYSC_connect+0x470/0x470 [ 36.594088] ? find_held_lock+0x35/0x1d0 [ 36.598120] ? exit_to_usermode_loop+0x98/0x300 [ 36.602763] exit_to_usermode_loop+0x224/0x300 [ 36.607316] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 36.612835] ? handle_mm_fault+0x4e3/0x940 [ 36.617033] ? down_read_trylock+0xdb/0x170 [ 36.621329] syscall_return_slowpath+0x42f/0x500 [ 36.626054] ? prepare_exit_to_usermode+0x2c0/0x2c0 [ 36.631044] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 36.635952] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 36.640936] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 36.645664] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 36.650387] RIP: 0033:0x445dd9 [ 36.653543] RSP: 002b:00007f7ed57a8db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 36.661219] RAX: 000000000000009b RBX: 0000000000000000 RCX: 0000000000445dd9 [ 36.668466] RDX: 000000000000009b RSI: 0000000020381000 RDI: 0000000000000003 [ 36.675703] RBP: 0000000000000000 R08: 0000000020a63ff0 R09: 0000000000000010 [ 36.682941] R10: 0000000000004000 R11: 0000000000000212 R12: 0000000000000000 [ 36.690176] R13: 00000000007efe8f R14: 00007f7ed57a99c0 R15: 0000000000000000 [ 36.697859] Dumping ftrace buffer: [ 36.701411] (ftrace buffer empty) [ 36.705092] Kernel Offset: disabled [ 36.708688] Rebooting in 86400 seconds..