serialport: Connected to syzkaller.us-central1-c.ci-upstream-kasan-gce-0 port 1 (session ID: df87c5ebdaa7dc6e4c0c1538ee9d7e1f28b1f0748617632e55dc94fd2e57ed5f, 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-0,10.128.0.43' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 60.391065] refcount_t: underflow; use-after-free. [ 60.391886] ------------[ cut here ]------------ [ 60.392669] WARNING: CPU: 1 PID: 2919 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 60.393847] Kernel panic - not syncing: panic_on_warn set ... [ 60.393847] [ 60.394873] CPU: 1 PID: 2919 Comm: syzkaller027162 Not tainted 4.13.0-rc3+ #12 [ 60.395878] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.397163] Call Trace: [ 60.397529] dump_stack+0x194/0x257 [ 60.398016] ? arch_local_irq_restore+0x53/0x53 [ 60.398647] panic+0x1e4/0x417 [ 60.399106] ? __warn+0x1d9/0x1d9 [ 60.399591] ? show_regs_print_info+0x65/0x65 [ 60.400202] ? refcount_sub_and_test+0x167/0x1b0 [ 60.400860] __warn+0x1c4/0x1d9 [ 60.401325] ? refcount_sub_and_test+0x167/0x1b0 [ 60.401957] report_bug+0x211/0x2d0 [ 60.402450] fixup_bug+0x40/0x90 [ 60.402971] do_trap+0x260/0x390 [ 60.403447] do_error_trap+0x120/0x390 [ 60.404003] ? do_trap+0x390/0x390 [ 60.404481] ? refcount_sub_and_test+0x167/0x1b0 [ 60.405109] ? vprintk_emit+0x3ea/0x590 [ 60.405661] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 60.406309] do_invalid_op+0x1b/0x20 [ 60.406807] invalid_op+0x1e/0x30 [ 60.407269] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 60.407974] RSP: 0018:ffff8801d0d5e310 EFLAGS: 00010282 [ 60.408698] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 60.409680] RDX: 0000000000000026 RSI: 1ffff1003a1abc22 RDI: ffffed003a1abc56 [ 60.410628] RBP: ffff8801d0d5e3a0 R08: 0000000000000001 R09: 0000000000000000 [ 60.414250] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003a1abc63 [ 60.422182] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d1ac3a3c [ 60.430141] ? refcount_inc+0x50/0x50 [ 60.433914] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 60.438646] ? sctp_association_free+0x2d0/0x930 [ 60.443384] ? sctp_do_sm+0x28e7/0x6d90 [ 60.447327] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 60.452055] ? sctp_close+0x3c6/0x980 [ 60.455825] ? inet_release+0xed/0x1c0 [ 60.459692] sctp_wfree+0x183/0x620 [ 60.463294] ? __sctp_write_space+0x910/0x910 [ 60.467763] skb_release_head_state+0x124/0x200 [ 60.472399] skb_release_all+0x15/0x60 [ 60.476256] consume_skb+0x153/0x490 [ 60.479932] ? sctp_chunk_put+0x99/0x420 [ 60.483955] ? pskb_carve+0x1db0/0x1db0 [ 60.487894] ? sctp_chunk_hold+0x20/0x20 [ 60.491921] ? refcount_sub_and_test+0x115/0x1b0 [ 60.496662] ? refcount_inc+0x50/0x50 [ 60.500425] ? mark_held_locks+0xaf/0x100 [ 60.504538] ? sctp_datamsg_put+0x456/0x560 [ 60.508835] sctp_chunk_put+0x29c/0x420 [ 60.512777] ? sctp_chunk_hold+0x20/0x20 [ 60.516814] ? sctp_transport_dst_confirm+0x50/0x50 [ 60.521803] ? noop_count+0x40/0x40 [ 60.525403] sctp_chunk_free+0x53/0x60 [ 60.529265] __sctp_outq_teardown+0xc7d/0x15a0 [ 60.533820] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 60.538724] ? lock_downgrade+0x990/0x990 [ 60.542840] ? lock_release+0xa40/0xa40 [ 60.546785] ? __free_insn_slot+0x5c0/0x5c0 [ 60.551081] ? update_stack_state+0x700/0x700 [ 60.555546] ? print_usage_bug+0x480/0x480 [ 60.559745] ? print_usage_bug+0x480/0x480 [ 60.563949] ? is_bpf_text_address+0xa4/0x120 [ 60.568421] ? __kernel_text_address+0xae/0xe0 [ 60.572970] ? unwind_get_return_address+0x61/0xa0 [ 60.577867] ? __save_stack_trace+0x7e/0xd0 [ 60.582159] ? check_noncircular+0x20/0x20 [ 60.586371] ? print_usage_bug+0x480/0x480 [ 60.590573] ? SOFTIRQ_verbose+0x10/0x10 [ 60.594599] ? save_stack_trace+0x16/0x20 [ 60.598715] ? save_trace+0x11f/0x350 [ 60.602488] ? lock_acquire+0x1d5/0x580 [ 60.606426] ? lock_acquire+0x1d5/0x580 [ 60.610366] ? lock_timer_base+0x1a3/0x2b0 [ 60.614569] ? find_held_lock+0x35/0x1d0 [ 60.618607] ? sock_def_wakeup+0x1f9/0x350 [ 60.622810] ? lock_downgrade+0x990/0x990 [ 60.626928] ? lock_release+0xa40/0xa40 [ 60.630876] sctp_outq_free+0x15/0x20 [ 60.634644] sctp_association_free+0x2d0/0x930 [ 60.639195] ? sctp_asconf_queue_teardown+0x700/0x700 [ 60.644350] ? sock_def_wakeup+0x222/0x350 [ 60.648586] ? sk_dst_check+0x560/0x560 [ 60.652536] ? sctp_association_put+0x74/0x2f0 [ 60.657084] ? sctp_association_hold+0x20/0x20 [ 60.661726] ? print_usage_bug+0x480/0x480 [ 60.665936] ? sctp_sm_lookup_event+0x95/0x3c0 [ 60.670491] sctp_do_sm+0x28e7/0x6d90 [ 60.674270] ? check_noncircular+0x20/0x20 [ 60.678494] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 60.684522] ? print_usage_bug+0x480/0x480 [ 60.688719] ? exit_to_usermode_loop+0x21c/0x2d0 [ 60.693438] ? syscall_return_slowpath+0x3a7/0x450 [ 60.698335] ? print_usage_bug+0x480/0x480 [ 60.702535] ? find_held_lock+0x35/0x1d0 [ 60.706576] ? find_held_lock+0x35/0x1d0 [ 60.710612] ? skb_dequeue+0x12a/0x180 [ 60.714466] ? lock_downgrade+0x990/0x990 [ 60.718583] ? do_raw_spin_trylock+0x190/0x190 [ 60.723134] ? mark_held_locks+0xaf/0x100 [ 60.727256] ? trace_hardirqs_on+0xd/0x10 [ 60.731377] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 60.735930] sctp_close+0x3c6/0x980 [ 60.739531] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 60.744772] ? unwind_get_return_address+0x61/0xa0 [ 60.749759] ? trace_hardirqs_off+0xd/0x10 [ 60.753969] ? _raw_spin_unlock_irqrestore+0xa6/0xba [ 60.759045] ? check_noncircular+0x20/0x20 [ 60.763257] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 60.767725] ? ipv6_sock_mc_close+0x148/0x1a0 [ 60.772191] ? ipv6_sock_ac_drop+0x580/0x580 [ 60.776660] ? ip_mc_drop_socket+0x1ce/0x230 [ 60.781047] ? __fsnotify_parent+0xb4/0x3a0 [ 60.785384] inet_release+0xed/0x1c0 [ 60.789089] inet6_release+0x50/0x70 [ 60.792777] sock_release+0x8d/0x1e0 [ 60.796474] ? sock_release+0x1e0/0x1e0 [ 60.800424] sock_close+0x16/0x20 [ 60.803848] __fput+0x327/0x7e0 [ 60.807099] ? fput+0x140/0x140 [ 60.810348] ? do_raw_spin_trylock+0x190/0x190 [ 60.814902] ? check_same_owner+0x320/0x320 [ 60.819202] ____fput+0x15/0x20 [ 60.822450] task_work_run+0x18a/0x260 [ 60.826317] ? task_work_cancel+0x210/0x210 [ 60.830641] ? _raw_spin_unlock+0x22/0x30 [ 60.834773] ? switch_task_namespaces+0x87/0xc0 [ 60.839424] do_exit+0xa32/0x1b10 [ 60.842850] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 60.848014] ? print_usage_bug+0x480/0x480 [ 60.852228] ? exit_notify+0xb10/0xb10 [ 60.856087] ? check_noncircular+0x20/0x20 [ 60.860292] ? check_noncircular+0x20/0x20 [ 60.864499] ? find_held_lock+0x35/0x1d0 [ 60.868530] ? find_held_lock+0x35/0x1d0 [ 60.872562] ? check_noncircular+0x20/0x20 [ 60.876765] ? check_noncircular+0x20/0x20 [ 60.880965] ? lock_downgrade+0x990/0x990 [ 60.885089] ? do_raw_spin_trylock+0x190/0x190 [ 60.889638] ? reacquire_held_locks+0x1fd/0x3d0 [ 60.894268] ? mark_held_locks+0xaf/0x100 [ 60.898379] ? reacquire_held_locks+0x1fd/0x3d0 [ 60.903013] ? check_noncircular+0x20/0x20 [ 60.907212] ? find_held_lock+0x35/0x1d0 [ 60.911249] ? release_sock+0x1d4/0x2a0 [ 60.915187] ? lock_downgrade+0x990/0x990 [ 60.919297] ? lock_downgrade+0x990/0x990 [ 60.923417] ? find_held_lock+0x35/0x1d0 [ 60.927453] ? get_signal+0x855/0x17e0 [ 60.931311] ? lock_downgrade+0x990/0x990 [ 60.935436] do_group_exit+0x149/0x400 [ 60.939290] ? __lock_is_held+0xb6/0x140 [ 60.943324] ? SyS_exit+0x30/0x30 [ 60.946753] ? _raw_spin_unlock_irq+0x27/0x70 [ 60.951216] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 60.956205] get_signal+0x7e8/0x17e0 [ 60.959929] ? ptrace_notify+0x130/0x130 [ 60.963962] ? inet_autobind+0x1f/0x180 [ 60.967909] ? __local_bh_enable_ip+0x9d/0x160 [ 60.972459] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 60.977444] ? release_sock+0x1d4/0x2a0 [ 60.981383] ? trace_hardirqs_on+0xd/0x10 [ 60.985501] ? __local_bh_enable_ip+0x9d/0x160 [ 60.990053] ? _raw_spin_unlock_bh+0x30/0x40 [ 60.994427] ? release_sock+0x1d4/0x2a0 [ 60.998385] ? trace_hardirqs_on+0xd/0x10 [ 61.002513] do_signal+0x94/0x1ee0 [ 61.006025] ? inet_sendmsg+0x11f/0x5e0 [ 61.009959] ? inet_sendmsg+0x126/0x5e0 [ 61.013900] ? __might_sleep+0x95/0x190 [ 61.017850] ? setup_sigcontext+0x7d0/0x7d0 [ 61.022137] ? selinux_socket_sendmsg+0x36/0x40 [ 61.026789] ? security_socket_sendmsg+0x89/0xb0 [ 61.031511] ? inet_recvmsg+0x5f0/0x5f0 [ 61.035452] ? sock_sendmsg+0x4f/0x110 [ 61.039319] ? fput+0xd2/0x140 [ 61.042477] ? SYSC_sendto+0x40d/0x5a0 [ 61.046334] ? SYSC_connect+0x470/0x470 [ 61.050465] ? find_held_lock+0x35/0x1d0 [ 61.054499] ? exit_to_usermode_loop+0x98/0x2d0 [ 61.059145] exit_to_usermode_loop+0x21c/0x2d0 [ 61.063703] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 61.069209] ? down_read_trylock+0xdb/0x170 [ 61.073496] ? __do_page_fault+0x2b8/0xb60 [ 61.077712] syscall_return_slowpath+0x3a7/0x450 [ 61.082445] ? prepare_exit_to_usermode+0x220/0x220 [ 61.087440] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 61.092336] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 61.097328] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 61.102207] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 61.106928] RIP: 0033:0x445469 [ 61.110083] RSP: 002b:00007fa061df3db8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c [ 61.117754] RAX: 0000000000000006 RBX: 0000000000000000 RCX: 0000000000445469 [ 61.124990] RDX: 0000000000000006 RSI: 0000000020aa7000 RDI: 0000000000000003 [ 61.132228] RBP: 0000000000000000 R08: 0000000020aa7000 R09: 000000000000001c [ 61.139469] R10: 0000000000008000 R11: 0000000000000212 R12: 0000000000000000 [ 61.146706] R13: 00007ffcb8d4dfff R14: 00007fa061df49c0 R15: 0000000000000000 [ 61.154359] Dumping ftrace buffer: [ 61.157931] (ftrace buffer empty) [ 61.161612] Kernel Offset: disabled [ 61.165206] Rebooting in 86400 seconds..