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-5,10.128.0.30' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 34.212651] refcount_t: underflow; use-after-free. [ 34.213471] ------------[ cut here ]------------ [ 34.214343] WARNING: CPU: 1 PID: 2987 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 34.215495] Kernel panic - not syncing: panic_on_warn set ... [ 34.215495] [ 34.216464] CPU: 1 PID: 2987 Comm: syzkaller789090 Not tainted 4.14.0-rc5+ #140 [ 34.217436] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.218654] Call Trace: [ 34.219013] dump_stack+0x194/0x257 [ 34.219503] ? arch_local_irq_restore+0x53/0x53 [ 34.220135] panic+0x1e4/0x417 [ 34.220566] ? __warn+0x1d9/0x1d9 [ 34.221031] ? show_regs_print_info+0x65/0x65 [ 34.221640] ? refcount_sub_and_test+0x167/0x1b0 [ 34.222273] __warn+0x1c4/0x1d9 [ 34.222714] ? refcount_sub_and_test+0x167/0x1b0 [ 34.223346] report_bug+0x211/0x2d0 [ 34.223838] fixup_bug+0x40/0x90 [ 34.224293] do_trap+0x260/0x390 [ 34.224752] do_error_trap+0x120/0x390 [ 34.225271] ? vprintk_emit+0x49b/0x590 [ 34.225804] ? do_trap+0x390/0x390 [ 34.226283] ? refcount_sub_and_test+0x167/0x1b0 [ 34.226913] ? vprintk_emit+0x3ea/0x590 [ 34.227452] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 34.228099] do_invalid_op+0x1b/0x20 [ 34.228601] invalid_op+0x18/0x20 [ 34.229079] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 34.229786] RSP: 0018:ffff8801d2106978 EFLAGS: 00010286 [ 34.230511] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 34.231461] RDX: 0000000000000026 RSI: 1ffff1003a420cef RDI: ffffed003a420d23 [ 34.232410] RBP: ffff8801d2106a08 R08: 0000000000000001 R09: 0000000000000000 [ 34.233360] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a420d30 [ 34.240598] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801dadd9a3c [ 34.247857] ? refcount_sub_and_test+0x167/0x1b0 [ 34.252578] ? refcount_inc+0x50/0x50 [ 34.256345] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 34.261064] ? sctp_association_free+0x2d0/0x930 [ 34.265787] ? sctp_do_sm+0x28e7/0x6dd0 [ 34.269727] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 34.274471] ? sctp_close+0x3c6/0x980 [ 34.278249] ? inet_release+0xed/0x1c0 [ 34.282126] sctp_wfree+0x183/0x620 [ 34.285724] ? __sctp_write_space+0x910/0x910 [ 34.290191] skb_release_head_state+0x124/0x200 [ 34.294830] skb_release_all+0x15/0x60 [ 34.298682] consume_skb+0x153/0x490 [ 34.302362] ? sctp_chunk_put+0x99/0x420 [ 34.306390] ? alloc_skb_with_frags+0x710/0x710 [ 34.311025] ? sctp_chunk_hold+0x20/0x20 [ 34.315058] ? refcount_sub_and_test+0x115/0x1b0 [ 34.319779] ? refcount_inc+0x50/0x50 [ 34.323549] ? mark_held_locks+0xaf/0x100 [ 34.327663] ? sctp_datamsg_put+0x456/0x560 [ 34.331958] sctp_chunk_put+0x29c/0x420 [ 34.335900] ? sctp_chunk_hold+0x20/0x20 [ 34.339932] ? sctp_transport_dst_confirm+0x50/0x50 [ 34.344916] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 34.350071] ? lock_release+0xa40/0xa40 [ 34.354018] ? show_initstate+0xb0/0xb0 [ 34.357962] sctp_chunk_free+0x53/0x60 [ 34.361817] __sctp_outq_teardown+0xc7d/0x15a0 [ 34.366374] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 34.371449] ? rcutorture_record_progress+0x10/0x10 [ 34.376438] ? is_bpf_text_address+0xa4/0x120 [ 34.380902] ? kernel_text_address+0x102/0x140 [ 34.385449] ? __kernel_text_address+0xd/0x40 [ 34.389912] ? unwind_get_return_address+0x61/0xa0 [ 34.394808] ? __save_stack_trace+0x7e/0xd0 [ 34.399106] ? add_lock_to_list.isra.33+0x292/0x39b [ 34.404098] ? check_noncircular+0x20/0x20 [ 34.408302] ? print_irqtrace_events+0x270/0x270 [ 34.413031] ? lock_acquire+0x1d5/0x580 [ 34.416973] ? lock_acquire+0x1d5/0x580 [ 34.420914] ? lock_timer_base+0x1a3/0x2b0 [ 34.425119] ? find_held_lock+0x35/0x1d0 [ 34.429152] ? sock_def_wakeup+0x1f9/0x350 [ 34.433353] ? lock_downgrade+0x990/0x990 [ 34.437470] ? lock_release+0xa40/0xa40 [ 34.441417] sctp_outq_free+0x15/0x20 [ 34.445183] sctp_association_free+0x2d0/0x930 [ 34.449736] ? sctp_asconf_queue_teardown+0x700/0x700 [ 34.454891] ? sock_def_wakeup+0x222/0x350 [ 34.459095] ? sk_dst_check+0x560/0x560 [ 34.463036] ? sctp_association_put+0x74/0x2f0 [ 34.467584] ? sctp_association_hold+0x20/0x20 [ 34.472141] sctp_do_sm+0x28e7/0x6dd0 [ 34.475920] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 34.481948] ? __free_insn_slot+0x5c0/0x5c0 [ 34.486238] ? print_irqtrace_events+0x270/0x270 [ 34.490975] ? print_irqtrace_events+0x270/0x270 [ 34.495709] ? find_held_lock+0x35/0x1d0 [ 34.499743] ? skb_dequeue+0x12a/0x180 [ 34.503597] ? lock_downgrade+0x990/0x990 [ 34.507717] ? do_raw_spin_trylock+0x190/0x190 [ 34.512269] ? mark_held_locks+0xaf/0x100 [ 34.516391] ? trace_hardirqs_on+0xd/0x10 [ 34.520512] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 34.525066] sctp_close+0x3c6/0x980 [ 34.528764] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 34.534009] ? unwind_get_return_address+0x61/0xa0 [ 34.538906] ? __save_stack_trace+0x7e/0xd0 [ 34.543204] ? check_noncircular+0x20/0x20 [ 34.547410] ? check_noncircular+0x20/0x20 [ 34.551617] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 34.556101] ? ipv6_sock_mc_close+0x148/0x1a0 [ 34.560567] ? ip_mc_drop_socket+0x1ce/0x230 [ 34.564941] ? __fsnotify_parent+0xb4/0x3a0 [ 34.569232] inet_release+0xed/0x1c0 [ 34.572915] inet6_release+0x50/0x70 [ 34.576597] sock_release+0x8d/0x1e0 [ 34.580279] ? sock_release+0x1e0/0x1e0 [ 34.584219] sock_close+0x16/0x20 [ 34.587640] __fput+0x327/0x7e0 [ 34.590891] ? fput+0x140/0x140 [ 34.594142] ? _raw_spin_unlock_irq+0x27/0x70 [ 34.598607] ____fput+0x15/0x20 [ 34.601857] task_work_run+0x199/0x270 [ 34.605720] ? task_work_cancel+0x210/0x210 [ 34.610008] ? _raw_spin_unlock+0x22/0x30 [ 34.614123] ? switch_task_namespaces+0x87/0xc0 [ 34.618767] do_exit+0x9b5/0x1ad0 [ 34.622185] ? __fd_install+0x2da/0x6a0 [ 34.626130] ? mm_update_next_owner+0x930/0x930 [ 34.630770] ? __lock_is_held+0xb6/0x140 [ 34.634809] ? __fd_install+0x2f7/0x6a0 [ 34.638753] ? get_unused_fd_flags+0x190/0x190 [ 34.643307] ? __might_sleep+0x95/0x190 [ 34.647256] ? kasan_check_read+0x11/0x20 [ 34.651368] ? _copy_to_user+0xa2/0xc0 [ 34.655228] ? fd_install+0x4d/0x60 [ 34.658827] ? SYSC_accept4+0x4ec/0x850 [ 34.662769] ? __release_sock+0x360/0x360 [ 34.666886] ? kernel_accept+0x2f0/0x2f0 [ 34.670920] ? sctp_inet_listen+0x141/0x850 [ 34.675209] ? sctp_transport_get_idx+0x70/0x70 [ 34.679846] ? selinux_socket_listen+0x36/0x40 [ 34.684394] ? security_socket_listen+0x81/0xb0 [ 34.689036] do_group_exit+0x149/0x400 [ 34.692888] ? SyS_bind+0x30/0x30 [ 34.696310] ? SyS_exit+0x30/0x30 [ 34.699731] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 34.704715] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 34.709439] SyS_exit_group+0x1d/0x20 [ 34.713207] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 34.717931] RIP: 0033:0x43e9d8 [ 34.721088] RSP: 002b:00007ffdb8b87018 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 34.728759] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9d8 [ 34.735992] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 34.743229] RBP: 0000000000000082 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 34.750465] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401700 [ 34.757698] R13: 0000000000401790 R14: 0000000000000000 R15: 0000000000000000 [ 34.765129] Dumping ftrace buffer: [ 34.768693] (ftrace buffer empty) [ 34.772369] Kernel Offset: disabled [ 34.775964] Rebooting in 86400 seconds..