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-386-1,10.128.15.221' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 42.618301] refcount_t: underflow; use-after-free. [ 42.623395] ------------[ cut here ]------------ [ 42.628268] WARNING: CPU: 0 PID: 2985 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 42.636944] Kernel panic - not syncing: panic_on_warn set ... [ 42.636944] [ 42.644293] CPU: 0 PID: 2985 Comm: syzkaller548394 Not tainted 4.14.0-rc2+ #12 [ 42.651627] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.660967] Call Trace: [ 42.663543] dump_stack+0x194/0x257 [ 42.667145] ? arch_local_irq_restore+0x53/0x53 [ 42.671798] panic+0x1e4/0x417 [ 42.674964] ? __warn+0x1d9/0x1d9 [ 42.678388] ? show_regs_print_info+0x65/0x65 [ 42.682869] ? refcount_sub_and_test+0x167/0x1b0 [ 42.687595] __warn+0x1c4/0x1d9 [ 42.690854] ? refcount_sub_and_test+0x167/0x1b0 [ 42.695594] report_bug+0x211/0x2d0 [ 42.699198] fixup_bug+0x40/0x90 [ 42.702536] do_trap+0x260/0x390 [ 42.705880] do_error_trap+0x120/0x390 [ 42.709741] ? do_trap+0x390/0x390 [ 42.713256] ? refcount_sub_and_test+0x167/0x1b0 [ 42.717982] ? vprintk_emit+0x3ea/0x590 [ 42.721934] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.726754] do_invalid_op+0x1b/0x20 [ 42.730438] invalid_op+0x18/0x20 [ 42.733860] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 42.739190] RSP: 0018:ffff8801ce67e370 EFLAGS: 00010282 [ 42.744525] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 42.751771] RDX: 0000000000000026 RSI: 1ffff10039ccfc2e RDI: ffffed0039ccfc62 [ 42.759024] RBP: ffff8801ce67e400 R08: ffff8801ce67da60 R09: 0000000000000000 [ 42.766268] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039ccfc6f [ 42.773508] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801cdc81364 [ 42.780790] ? refcount_inc+0x50/0x50 [ 42.784563] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 42.789290] ? sctp_association_free+0x2d0/0x930 [ 42.794014] ? sctp_do_sm+0x28e7/0x6dd0 [ 42.797957] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 42.802748] ? sctp_close+0x3c6/0x980 [ 42.806519] ? inet_release+0xed/0x1c0 [ 42.810382] sctp_wfree+0x183/0x620 [ 42.813979] ? __sctp_write_space+0x910/0x910 [ 42.818446] skb_release_head_state+0x124/0x200 [ 42.823086] skb_release_all+0x15/0x60 [ 42.826942] consume_skb+0x153/0x490 [ 42.830624] ? sctp_chunk_put+0x99/0x420 [ 42.834654] ? alloc_skb_with_frags+0x710/0x710 [ 42.839293] ? sctp_chunk_hold+0x20/0x20 [ 42.843327] ? refcount_sub_and_test+0x115/0x1b0 [ 42.848054] ? refcount_inc+0x50/0x50 [ 42.851824] ? mark_held_locks+0xb2/0x100 [ 42.856108] ? sctp_datamsg_put+0x456/0x560 [ 42.860409] sctp_chunk_put+0x29c/0x420 [ 42.864356] ? sctp_chunk_hold+0x20/0x20 [ 42.868392] ? sctp_transport_dst_confirm+0x50/0x50 [ 42.873397] sctp_chunk_free+0x53/0x60 [ 42.877255] __sctp_outq_teardown+0xc7d/0x15a0 [ 42.881817] ? inet6_release+0x50/0x70 [ 42.885686] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 42.890588] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 42.895577] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 42.900564] ? unwind_dump+0x4c0/0x4c0 [ 42.904425] ? unwind_dump+0x4c0/0x4c0 [ 42.908288] ? copy_trace+0x1d0/0x1d0 [ 42.912066] ? check_noncircular+0x20/0x20 [ 42.916273] ? check_noncircular+0x20/0x20 [ 42.920476] ? unwind_get_return_address+0x61/0xa0 [ 42.925377] ? __save_stack_trace+0x61/0xd0 [ 42.929669] ? check_noncircular+0x20/0x20 [ 42.933877] ? print_usage_bug+0x480/0x480 [ 42.938095] ? find_held_lock+0x39/0x1d0 [ 42.942144] ? lock_downgrade+0x990/0x990 [ 42.946272] ? sk_dst_check+0x560/0x560 [ 42.950221] ? rcu_read_lock_sched_held+0x108/0x120 [ 42.955217] ? lock_release+0xd70/0xd70 [ 42.959176] sctp_outq_free+0x15/0x20 [ 42.962952] sctp_association_free+0x2d0/0x930 [ 42.967514] ? sctp_asconf_queue_teardown+0x700/0x700 [ 42.972704] ? sock_def_wakeup+0x222/0x350 [ 42.976917] ? sk_dst_check+0x560/0x560 [ 42.980867] ? sctp_association_put+0x74/0x2f0 [ 42.985421] ? sctp_association_hold+0x20/0x20 [ 42.989975] ? unwind_dump+0x4c0/0x4c0 [ 42.993843] sctp_do_sm+0x28e7/0x6dd0 [ 42.997628] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 43.003663] ? print_usage_bug+0x480/0x480 [ 43.007866] ? __lock_acquire+0x20fd/0x4620 [ 43.012167] ? print_usage_bug+0x480/0x480 [ 43.016393] ? find_held_lock+0x39/0x1d0 [ 43.020439] ? lock_downgrade+0x990/0x990 [ 43.024577] ? skb_dequeue+0x22/0x180 [ 43.028356] ? do_raw_spin_trylock+0x190/0x190 [ 43.032913] ? mark_held_locks+0xb2/0x100 [ 43.037040] ? trace_hardirqs_on+0xd/0x10 [ 43.041166] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 43.045723] sctp_close+0x3c6/0x980 [ 43.049330] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 43.054576] ? unwind_get_return_address+0x61/0xa0 [ 43.059478] ? check_noncircular+0x20/0x20 [ 43.063688] ? depot_save_stack+0x3b5/0x490 [ 43.067989] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 43.072462] ? ipv6_sock_mc_close+0x148/0x1a0 [ 43.076937] ? ip_mc_drop_socket+0x1ce/0x230 [ 43.081317] ? __fsnotify_parent+0xb4/0x3a0 [ 43.085621] inet_release+0xed/0x1c0 [ 43.089311] inet6_release+0x50/0x70 [ 43.092999] sock_release+0x8d/0x1e0 [ 43.096695] ? sock_release+0x1e0/0x1e0 [ 43.100640] sock_close+0x16/0x20 [ 43.104067] __fput+0x333/0x7f0 [ 43.107330] ? fput+0x140/0x140 [ 43.110608] ? _raw_spin_unlock_irq+0x27/0x70 [ 43.115084] ____fput+0x15/0x20 [ 43.118339] task_work_run+0x199/0x270 [ 43.122202] ? task_work_cancel+0x210/0x210 [ 43.126496] ? _raw_spin_unlock+0x22/0x30 [ 43.130614] ? switch_task_namespaces+0x87/0xc0 [ 43.135258] do_exit+0x9d2/0x1af0 [ 43.138686] ? find_held_lock+0x39/0x1d0 [ 43.142720] ? mm_update_next_owner+0x930/0x930 [ 43.147365] ? lock_downgrade+0x990/0x990 [ 43.151481] ? lock_downgrade+0x990/0x990 [ 43.155607] ? release_sock+0x74/0x2a0 [ 43.159483] ? do_raw_spin_trylock+0x190/0x190 [ 43.164037] ? trace_hardirqs_on+0xd/0x10 [ 43.168154] ? __local_bh_enable_ip+0x9d/0x160 [ 43.172706] ? check_noncircular+0x20/0x20 [ 43.176914] ? release_sock+0x1d4/0x2a0 [ 43.180860] ? trace_hardirqs_on+0xd/0x10 [ 43.184978] ? __local_bh_enable_ip+0x9d/0x160 [ 43.189533] ? _raw_spin_unlock_bh+0x30/0x40 [ 43.193916] ? release_sock+0x1d4/0x2a0 [ 43.197862] ? sctp_shutdown+0x2d0/0x2d0 [ 43.201899] ? __release_sock+0x360/0x360 [ 43.206024] ? find_held_lock+0x39/0x1d0 [ 43.210066] ? lock_downgrade+0x990/0x990 [ 43.214182] ? recalc_sigpending_tsk+0x117/0x150 [ 43.218913] ? recalc_sigpending+0x103/0x160 [ 43.223294] ? recalc_sigpending_tsk+0x150/0x150 [ 43.228019] ? get_signal+0x2b2/0x16d0 [ 43.231890] do_group_exit+0x149/0x400 [ 43.235749] ? __lock_is_held+0xbc/0x140 [ 43.239781] ? SyS_exit+0x30/0x30 [ 43.243217] ? _raw_spin_unlock_irq+0x27/0x70 [ 43.247687] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 43.252688] get_signal+0x73f/0x16d0 [ 43.256405] ? ptrace_notify+0x130/0x130 [ 43.260455] ? inet_sendmsg+0x11f/0x5e0 [ 43.264400] ? inet_sendmsg+0x126/0x5e0 [ 43.268346] ? __might_sleep+0x95/0x190 [ 43.272301] ? inet_recvmsg+0x5f0/0x5f0 [ 43.276294] ? selinux_socket_sendmsg+0x36/0x40 [ 43.280950] ? security_socket_sendmsg+0x89/0xb0 [ 43.285683] do_signal+0x94/0x1ee0 [ 43.289194] ? sock_sendmsg+0x4f/0x110 [ 43.293051] ? fput+0xd2/0x140 [ 43.296214] ? SYSC_sendto+0x413/0x5a0 [ 43.300092] ? setup_sigcontext+0x7d0/0x7d0 [ 43.304397] ? lock_downgrade+0x990/0x990 [ 43.308542] ? exit_to_usermode_loop+0x8c/0x310 [ 43.313190] exit_to_usermode_loop+0x214/0x310 [ 43.317742] ? vmacache_update+0xfe/0x130 [ 43.321863] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 43.327383] ? SyS_sendto+0x40/0x50 [ 43.330989] do_fast_syscall_32+0x83e/0xf05 [ 43.335290] ? do_int80_syscall_32+0x940/0x940 [ 43.339849] ? lockdep_sys_exit+0x47/0xf0 [ 43.343980] ? syscall_return_slowpath+0x2b3/0x510 [ 43.348884] ? finish_task_switch+0x1aa/0x740 [ 43.353356] ? retint_user+0x18/0x20 [ 43.357046] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.361869] entry_SYSENTER_compat+0x51/0x60 [ 43.366269] RIP: 0023:0xf7fd1c79 [ 43.369605] RSP: 002b:00000000f6fcb1ec EFLAGS: 00000292 ORIG_RAX: 0000000000000171 [ 43.377302] RAX: 0000000000000006 RBX: 0000000000000003 RCX: 0000000020aa7000 [ 43.384556] RDX: 0000000000000006 RSI: 0000000000008000 RDI: 0000000020aa7000 [ 43.391797] RBP: 000000000000001c R08: 0000000000000000 R09: 0000000000000000 [ 43.399037] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 43.406278] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 43.413741] Dumping ftrace buffer: [ 43.417308] (ftrace buffer empty) [ 43.420992] Kernel Offset: disabled [ 43.424597] Rebooting in 86400 seconds..