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-9,10.128.0.62' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 31.298432] refcount_t: underflow; use-after-free. [ 31.299279] ------------[ cut here ]------------ [ 31.299923] WARNING: CPU: 0 PID: 2975 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 [ 31.301177] Kernel panic - not syncing: panic_on_warn set ... [ 31.301177] [ 31.302150] CPU: 0 PID: 2975 Comm: syzkaller322468 Not tainted 4.13.0-mm1+ #6 [ 31.303119] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.304357] Call Trace: [ 31.304722] dump_stack+0x194/0x257 [ 31.305234] ? arch_local_irq_restore+0x53/0x53 [ 31.305873] panic+0x1e4/0x417 [ 31.306308] ? __warn+0x1d9/0x1d9 [ 31.306777] ? show_regs_print_info+0x65/0x65 [ 31.307420] ? refcount_sub_and_test+0x167/0x1b0 [ 31.308057] __warn+0x1c4/0x1d9 [ 31.308503] ? refcount_sub_and_test+0x167/0x1b0 [ 31.309142] report_bug+0x211/0x2d0 [ 31.309647] fixup_bug+0x40/0x90 [ 31.310109] do_trap+0x260/0x390 [ 31.310577] do_error_trap+0x120/0x390 [ 31.311121] ? do_trap+0x390/0x390 [ 31.311603] ? refcount_sub_and_test+0x167/0x1b0 [ 31.312239] ? vprintk_emit+0x3ea/0x590 [ 31.312785] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.313438] do_invalid_op+0x1b/0x20 [ 31.313940] invalid_op+0x18/0x20 [ 31.314411] RIP: 0010:refcount_sub_and_test+0x167/0x1b0 [ 31.315134] RSP: 0018:ffff8801cebfe920 EFLAGS: 00010286 [ 31.315853] RAX: 0000000000000026 RBX: 0000000000000001 RCX: 0000000000000000 [ 31.316839] RDX: 0000000000000026 RSI: 1ffff10039d7fce4 RDI: ffffed0039d7fd18 [ 31.317809] RBP: ffff8801cebfe9b0 R08: ffff8801cebfe010 R09: 0000000000000000 [ 31.318767] R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10039d7fd25 [ 31.326008] R13: 00000000ffffff01 R14: 0000000000000100 R15: ffff8801d28c4ae4 [ 31.333271] ? refcount_inc+0x50/0x50 [ 31.337041] ? __sctp_outq_teardown+0xc7d/0x15a0 [ 31.341768] ? sctp_association_free+0x2d0/0x930 [ 31.346495] ? sctp_do_sm+0x28e7/0x6dd0 [ 31.350437] ? sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 31.355171] ? sctp_close+0x3c6/0x980 [ 31.358944] ? inet_release+0xed/0x1c0 [ 31.362808] sctp_wfree+0x183/0x620 [ 31.366406] ? __sctp_write_space+0x910/0x910 [ 31.370874] skb_release_head_state+0x124/0x200 [ 31.375512] skb_release_all+0x15/0x60 [ 31.379367] consume_skb+0x153/0x490 [ 31.383049] ? sctp_chunk_put+0x99/0x420 [ 31.387081] ? alloc_skb_with_frags+0x710/0x710 [ 31.391717] ? sctp_chunk_hold+0x20/0x20 [ 31.395754] ? refcount_sub_and_test+0x115/0x1b0 [ 31.400480] ? refcount_inc+0x50/0x50 [ 31.404249] ? mark_held_locks+0xb2/0x100 [ 31.408370] ? sctp_datamsg_put+0x456/0x560 [ 31.412669] sctp_chunk_put+0x29c/0x420 [ 31.416617] ? sctp_chunk_hold+0x20/0x20 [ 31.420652] ? sctp_transport_dst_confirm+0x50/0x50 [ 31.425656] sctp_chunk_free+0x53/0x60 [ 31.429516] __sctp_outq_teardown+0xc7d/0x15a0 [ 31.434068] ? inet6_release+0x50/0x70 [ 31.437933] ? sctp_inq_set_th_handler+0x1b0/0x1b0 [ 31.442835] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 31.447826] ? unwind_next_frame.part.6+0x1ae/0xc70 [ 31.452827] ? unwind_dump+0x4c0/0x4c0 [ 31.456687] ? unwind_dump+0x4c0/0x4c0 [ 31.460550] ? copy_trace+0x1d0/0x1d0 [ 31.464326] ? check_noncircular+0x20/0x20 [ 31.468532] ? check_noncircular+0x20/0x20 [ 31.472737] ? unwind_get_return_address+0x61/0xa0 [ 31.477641] ? __save_stack_trace+0x61/0xd0 [ 31.481938] ? check_noncircular+0x20/0x20 [ 31.486147] ? print_usage_bug+0x480/0x480 [ 31.490358] ? find_held_lock+0x39/0x1d0 [ 31.494402] ? lock_downgrade+0x990/0x990 [ 31.498528] ? sk_dst_check+0x560/0x560 [ 31.502472] ? rcu_read_lock_sched_held+0x108/0x120 [ 31.507464] ? lock_release+0xd70/0xd70 [ 31.511417] sctp_outq_free+0x15/0x20 [ 31.515190] sctp_association_free+0x2d0/0x930 [ 31.519746] ? sctp_asconf_queue_teardown+0x700/0x700 [ 31.524909] ? sock_def_wakeup+0x222/0x350 [ 31.529113] ? sk_dst_check+0x560/0x560 [ 31.533057] ? sctp_association_put+0x74/0x2f0 [ 31.537609] ? sctp_association_hold+0x20/0x20 [ 31.542162] ? unwind_dump+0x4c0/0x4c0 [ 31.546024] ? sctp_sm_lookup_event+0x95/0x3c0 [ 31.550578] sctp_do_sm+0x28e7/0x6dd0 [ 31.554363] ? sctp_do_8_2_transport_strike.isra.16+0x8a0/0x8a0 [ 31.560394] ? print_usage_bug+0x480/0x480 [ 31.564597] ? __lock_acquire+0x20fd/0x4620 [ 31.568893] ? print_usage_bug+0x480/0x480 [ 31.573103] ? find_held_lock+0x39/0x1d0 [ 31.577149] ? lock_downgrade+0x990/0x990 [ 31.581273] ? skb_dequeue+0x22/0x180 [ 31.585052] ? do_raw_spin_trylock+0x190/0x190 [ 31.589609] ? mark_held_locks+0xb2/0x100 [ 31.593736] ? trace_hardirqs_on+0xd/0x10 [ 31.597866] sctp_primitive_SHUTDOWN+0xa0/0xd0 [ 31.602424] sctp_close+0x3c6/0x980 [ 31.606032] ? sctp_apply_peer_addr_params+0xf30/0xf30 [ 31.611280] ? unwind_get_return_address+0x61/0xa0 [ 31.616183] ? check_noncircular+0x20/0x20 [ 31.620394] ? depot_save_stack+0x12c/0x490 [ 31.624700] ? ipv6_sock_ac_close+0x2e8/0x3e0 [ 31.629170] ? ipv6_sock_mc_close+0x148/0x1a0 [ 31.633647] ? ipv6_sock_ac_drop+0x580/0x580 [ 31.638025] ? ip_mc_drop_socket+0x1ce/0x230 [ 31.642404] ? __fsnotify_parent+0xb4/0x3a0 [ 31.646698] inet_release+0xed/0x1c0 [ 31.650387] inet6_release+0x50/0x70 [ 31.654072] sock_release+0x8d/0x1e0 [ 31.657757] ? sock_release+0x1e0/0x1e0 [ 31.661704] sock_close+0x16/0x20 [ 31.665133] __fput+0x333/0x7f0 [ 31.668391] ? fput+0x140/0x140 [ 31.671646] ? _raw_spin_unlock_irq+0x27/0x70 [ 31.676119] ____fput+0x15/0x20 [ 31.679374] task_work_run+0x199/0x270 [ 31.683233] ? task_work_cancel+0x210/0x210 [ 31.687526] ? _raw_spin_unlock+0x22/0x30 [ 31.691643] ? switch_task_namespaces+0x87/0xc0 [ 31.696287] do_exit+0xa52/0x1b40 [ 31.699717] ? get_unused_fd_flags+0x190/0x190 [ 31.704272] ? mm_update_next_owner+0x930/0x930 [ 31.708915] ? __lock_is_held+0xbc/0x140 [ 31.712958] ? __fd_install+0x2f7/0x6a0 [ 31.716908] ? get_unused_fd_flags+0x190/0x190 [ 31.721467] ? __might_sleep+0x95/0x190 [ 31.725417] ? kasan_check_read+0x11/0x20 [ 31.729534] ? _copy_to_user+0xa2/0xc0 [ 31.733396] ? fd_install+0x4d/0x60 [ 31.736994] ? SYSC_accept4+0x4f2/0x850 [ 31.740944] ? kernel_accept+0x2f0/0x2f0 [ 31.744985] ? do_page_fault+0xee/0x720 [ 31.748929] ? sctp_transport_get_idx+0x70/0x70 [ 31.753570] ? selinux_socket_listen+0x36/0x40 [ 31.758123] ? security_socket_listen+0x81/0xb0 [ 31.762770] do_group_exit+0x149/0x400 [ 31.766630] ? lockdep_sys_exit+0x47/0xf0 [ 31.770747] ? SyS_exit+0x30/0x30 [ 31.774171] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 31.779159] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 31.783887] SyS_exit_group+0x1d/0x20 [ 31.787658] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 31.792382] RIP: 0033:0x43e9d8 [ 31.795543] RSP: 002b:00007ffceb0b4198 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 31.803222] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e9d8 [ 31.810459] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 31.817696] RBP: 0000000000000082 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 31.824933] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401700 [ 31.832170] R13: 0000000000401790 R14: 0000000000000000 R15: 0000000000000000 [ 31.839880] Dumping ftrace buffer: [ 31.843430] (ftrace buffer empty) [ 31.847108] Kernel Offset: disabled [ 31.850714] Rebooting in 86400 seconds..