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-mmots-kasan-gce-0,10.128.0.50' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 40.079884] refcount_t: underflow; use-after-free. [ 40.080724] ------------[ cut here ]------------ [ 40.081645] WARNING: CPU: 1 PID: 2991 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 40.082803] Kernel panic - not syncing: panic_on_warn set ... [ 40.082803] [ 40.083817] CPU: 1 PID: 2991 Comm: syzkaller471780 Not tainted 4.14.0-rc5-mm1+ #19 [ 40.084846] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.086080] Call Trace: [ 40.086439] dump_stack+0x194/0x257 [ 40.086934] ? arch_local_irq_restore+0x53/0x53 [ 40.087563] ? vsnprintf+0x1ed/0x1900 [ 40.088080] panic+0x1e4/0x41c [ 40.088515] ? refcount_error_report+0x214/0x214 [ 40.089182] ? show_regs_print_info+0x65/0x65 [ 40.089791] ? __warn+0x1a9/0x1e0 [ 40.090299] ? refcount_sub_and_test+0x167/0x1b0 [ 40.090945] __warn+0x1c4/0x1e0 [ 40.091389] ? refcount_sub_and_test+0x167/0x1b0 [ 40.092024] report_bug+0x211/0x2d0 [ 40.092519] fixup_bug+0x40/0x90 [ 40.092975] do_trap+0x260/0x390 [ 40.093437] do_error_trap+0x120/0x390 [ 40.093987] ? vprintk_emit+0x49b/0x590 [ 40.094523] ? do_trap+0x390/0x390 [ 40.095004] ? refcount_sub_and_test+0x167/0x1b0 [ 40.095636] ? vprintk_emit+0x3ea/0x590 [ 40.096179] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.096829] do_invalid_op+0x1b/0x20 [ 40.097345] invalid_op+0x18/0x20 [ 40.097810] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 40.098528] RSP: 0018:ffff8801c160ea38 EFLAGS: 00010282 [ 40.099237] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 40.101861] RDX: 0000000000000026 RSI: 1ffff100382c1d07 RDI: ffffed00382c1d3b [ 40.109101] RBP: ffff8801c160eac8 R08: 0000000000000001 R09: 0000000000000000 [ 40.116341] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff100382c1d48 [ 40.123577] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d3250a3c [ 40.130837] ? refcount_sub_and_test+0x167/0x1b0 [ 40.135560] ? refcount_inc+0x50/0x50 [ 40.139328] ? sctp_outq_free+0x15/0x20 [ 40.143269] ? sctp_do_sm+0x271b/0x6a30 [ 40.147207] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 40.151927] ? sctp_close+0x3c6/0x980 [ 40.155696] ? inet_release+0xed/0x1c0 [ 40.159551] ? inet6_release+0x50/0x70 [ 40.163409] sctp_wfree+0x183/0x620 [ 40.167004] ? __sctp_write_space+0x910/0x910 [ 40.171467] skb_release_head_state+0x124/0x200 [ 40.176106] skb_release_all+0x15/0x60 [ 40.179961] consume_skb+0x153/0x490 [ 40.183637] ? sctp_chunk_put+0x99/0x420 [ 40.187662] ? alloc_skb_with_frags+0x750/0x750 [ 40.192296] ? sctp_chunk_hold+0x20/0x20 [ 40.196325] ? refcount_sub_and_test+0x115/0x1b0 [ 40.201048] ? refcount_inc+0x50/0x50 [ 40.204814] ? mark_held_locks+0xaf/0x100 [ 40.208932] ? sctp_datamsg_put+0x456/0x560 [ 40.213227] sctp_chunk_put+0x29c/0x420 [ 40.217169] ? sctp_chunk_hold+0x20/0x20 [ 40.221197] ? sctp_transport_dst_confirm+0x50/0x50 [ 40.226182] ? sctp_sched_fcfs_dequeue+0x198/0x290 [ 40.231078] ? sctp_sched_dequeue_common+0x5d0/0x5d0 [ 40.236154] sctp_chunk_free+0x53/0x60 [ 40.240009] __sctp_outq_teardown+0xa5b/0x1230 [ 40.244567] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 40.249464] ? __kernel_text_address+0xd/0x40 [ 40.253925] ? unwind_get_return_address+0x61/0xa0 [ 40.258824] ? __save_stack_trace+0x7e/0xd0 [ 40.263117] ? add_lock_to_list.isra.32+0x292/0x39b [ 40.268112] ? check_noncircular+0x20/0x20 [ 40.272313] ? print_irqtrace_events+0x270/0x270 [ 40.277045] ? lock_acquire+0x1d5/0x580 [ 40.280983] ? lock_acquire+0x1d5/0x580 [ 40.284922] ? lock_timer_base+0x1a3/0x2b0 [ 40.289125] ? find_held_lock+0x35/0x1d0 [ 40.293158] ? sock_def_wakeup+0x1f9/0x350 [ 40.297360] ? lock_downgrade+0x990/0x990 [ 40.301478] ? lock_release+0xa40/0xa40 [ 40.305423] sctp_outq_free+0x15/0x20 [ 40.309191] sctp_association_free+0x2d0/0x930 [ 40.313745] ? sctp_asconf_queue_teardown+0x700/0x700 [ 40.318902] ? sock_def_wakeup+0x222/0x350 [ 40.323106] ? sk_dst_check+0x560/0x560 [ 40.327048] ? sctp_association_put+0x74/0x2f0 [ 40.331597] ? sctp_association_hold+0x20/0x20 [ 40.336158] sctp_do_sm+0x271b/0x6a30 [ 40.339937] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 40.345961] ? __free_insn_slot+0x5c0/0x5c0 [ 40.350248] ? print_irqtrace_events+0x270/0x270 [ 40.354974] ? print_irqtrace_events+0x270/0x270 [ 40.359713] ? find_held_lock+0x35/0x1d0 [ 40.363747] ? skb_dequeue+0x12a/0x180 [ 40.367601] ? lock_downgrade+0x990/0x990 [ 40.371718] ? do_raw_spin_trylock+0x190/0x190 [ 40.376268] ? mark_held_locks+0xaf/0x100 [ 40.380390] ? trace_hardirqs_on+0xd/0x10 [ 40.384513] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 40.389066] sctp_close+0x3c6/0x980 [ 40.392671] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 40.397914] ? unwind_get_return_address+0x61/0xa0 [ 40.402811] ? __save_stack_trace+0x7e/0xd0 [ 40.407099] ? check_noncircular+0x20/0x20 [ 40.411302] ? check_noncircular+0x20/0x20 [ 40.415509] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 40.419973] ? ipv6_sock_mc_close+0x148/0x1a0 [ 40.424437] ? ip_mc_drop_socket+0x1ce/0x230 [ 40.428813] ? __fsnotify_parent+0xb4/0x3a0 [ 40.433107] inet_release+0xed/0x1c0 [ 40.436792] inet6_release+0x50/0x70 [ 40.440474] sock_release+0x8d/0x1e0 [ 40.444155] ? sock_release+0x1e0/0x1e0 [ 40.448094] sock_close+0x16/0x20 [ 40.451515] __fput+0x327/0x7e0 [ 40.454766] ? fput+0x140/0x140 [ 40.458015] ? _raw_spin_unlock_irq+0x27/0x70 [ 40.462483] ____fput+0x15/0x20 [ 40.465730] task_work_run+0x199/0x270 [ 40.469588] ? task_work_cancel+0x210/0x210 [ 40.473878] ? _raw_spin_unlock+0x22/0x30 [ 40.477995] ? switch_task_namespaces+0x87/0xc0 [ 40.482634] do_exit+0x9b5/0x1ad0 [ 40.486053] ? __fd_install+0x2da/0x6a0 [ 40.490000] ? mm_update_next_owner+0x930/0x930 [ 40.494637] ? __lock_is_held+0xb6/0x140 [ 40.498677] ? __fd_install+0x2f7/0x6a0 [ 40.502624] ? get_unused_fd_flags+0x190/0x190 [ 40.507179] ? __might_sleep+0x95/0x190 [ 40.511126] ? kasan_check_read+0x11/0x20 [ 40.515239] ? _copy_to_user+0xa2/0xc0 [ 40.519100] ? fd_install+0x4d/0x60 [ 40.522698] ? SYSC_accept4+0x4ec/0x850 [ 40.526637] ? __release_sock+0x360/0x360 [ 40.530756] ? kernel_accept+0x2f0/0x2f0 [ 40.534789] ? sctp_inet_listen+0x141/0x850 [ 40.539085] ? sctp_transport_get_idx+0x70/0x70 [ 40.543722] ? selinux_socket_listen+0x36/0x40 [ 40.548272] ? security_socket_listen+0x81/0xb0 [ 40.552912] do_group_exit+0x149/0x400 [ 40.556764] ? SyS_bind+0x30/0x30 [ 40.560184] ? SyS_exit+0x30/0x30 [ 40.563607] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 40.568593] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 40.573316] SyS_exit_group+0x1d/0x20 [ 40.577082] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 40.581804] RIP: 0033:0x43e9d8 [ 40.584961] RSP: 002b:00007ffda9a4b278 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 40.592633] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9d8 [ 40.599869] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 40.607103] RBP: 0000000000000082 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 40.614337] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401700 [ 40.621570] R13: 0000000000401790 R14: 0000000000000000 R15: 0000000000000000 [ 40.628953] Dumping ftrace buffer: [ 40.632499] (ftrace buffer empty) [ 40.636175] Kernel Offset: disabled [ 40.639771] Rebooting in 86400 seconds..