syzkaller login: [ 13.634991] BUG: looking up invalid subclass: 8 [ 13.635994] turning off the locking correctness validator. [ 13.636679] CPU: 0 PID: 2988 Comm: syzkaller395259 Not tainted 4.14.0-rc7-next-20171103+ #10 [ 13.637681] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 executing program [ 13.638676] Call Trace: [ 13.638988] dump_stack+0x194/0x257 [ 13.639359] ? arch_local_irq_restore+0x53/0x53 [ 13.639780] register_lock_class+0x5f2/0x2c70 [ 13.640237] ? __is_insn_slot_addr+0x1fc/0x330 [ 13.640688] ? lock_downgrade+0x990/0x990 [ 13.641093] ? lock_pin_lock+0x370/0x370 [ 13.641494] ? check_usage+0x23d/0xb70 [ 13.641877] ? lock_release+0xd70/0xd70 [ 13.642391] ? is_bpf_text_address+0x7b/0x120 [ 13.642933] ? check_usage_forwards+0x430/0x430 [ 13.643794] ? trace_raw_output_xdp_redirect_map_err+0x440/0x440 [ 13.644595] ? __bfs+0xaa/0x750 [ 13.645006] ? lockdep_on+0x50/0x50 [ 13.645492] ? trace_hardirqs_off+0x10/0x10 [ 13.646065] ? rcutorture_record_progress+0x10/0x10 [ 13.646725] ? print_usage_bug+0x480/0x480 [ 13.647261] ? is_bpf_text_address+0xa4/0x120 [ 13.647865] ? print_usage_bug+0x480/0x480 [ 13.648421] ? check_prev_add+0x31a/0x1580 [ 13.648969] ? check_prev_add+0x31a/0x1580 [ 13.649536] ? copy_trace+0x1d0/0x1d0 [ 13.650051] ? check_usage+0xb70/0xb70 [ 13.650558] ? SOFTIRQ_verbose+0x10/0x10 [ 13.651090] ? save_stack_trace+0x1a/0x20 [ 13.651648] ? save_trace+0x11f/0x350 [ 13.652152] ? print_usage_bug+0x480/0x480 [ 13.652716] ? hlock_class+0x140/0x140 [ 13.653227] __lock_acquire+0x203/0x4770 [ 13.653760] ? __lock_acquire+0x739/0x4770 [ 13.654328] ? print_usage_bug+0x480/0x480 [ 13.654886] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 13.655575] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 13.656296] ? __lock_acquire+0x3374/0x4770 [ 13.656891] ? __lock_acquire+0x3374/0x4770 [ 13.657491] ? __lock_acquire+0x739/0x4770 [ 13.658086] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 13.658774] ? __lock_acquire+0x739/0x4770 [ 13.659306] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 13.659789] ? check_noncircular+0x20/0x20 [ 13.660140] ? check_noncircular+0x20/0x20 [ 13.660519] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 13.661122] ? debug_check_no_locks_freed+0x3d0/0x3d0 [ 13.661756] ? check_noncircular+0x20/0x20 [ 13.662217] ? find_held_lock+0x39/0x1d0 [ 13.662591] ? find_held_lock+0x39/0x1d0 [ 13.663002] lock_acquire+0x1d5/0x580 [ 13.663414] ? snd_seq_deliver_event+0x559/0x820 [ 13.663954] ? lock_release+0xd70/0xd70 [ 13.664329] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 13.665083] ? rcu_note_context_switch+0x710/0x710 [ 13.665532] ? __might_sleep+0x95/0x190 [ 13.666007] down_read_nested+0x9a/0x150 [ 13.666494] ? snd_seq_deliver_event+0x559/0x820 [ 13.667358] ? down_read_non_owner+0x40/0x40 [ 13.667904] ? _raw_read_unlock+0x22/0x30 [ 13.668391] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.668934] snd_seq_deliver_event+0x559/0x820 [ 13.669455] ? do_raw_spin_trylock+0x190/0x190 [ 13.669971] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.670716] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 13.671313] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.672008] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.672531] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.673124] dummy_input+0x2c4/0x400 [ 13.673558] ? dummy_free+0x20/0x20 [ 13.674066] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.674695] ? dummy_free+0x20/0x20 [ 13.675092] snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 [ 13.675935] ? snd_seq_ioctl_running_mode+0x150/0x150 [ 13.676646] ? snd_seq_timer_get_cur_tick+0xd/0x40 [ 13.677195] ? update_timestamp_of_queue+0x14d/0x200 [ 13.677806] snd_seq_deliver_event+0x362/0x820 [ 13.678360] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.679063] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.679625] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.680126] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.680705] dummy_input+0x2c4/0x400 [ 13.681085] ? dummy_free+0x20/0x20 [ 13.681437] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.681892] ? dummy_free+0x20/0x20 [ 13.682239] snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 [ 13.682845] ? snd_seq_ioctl_running_mode+0x150/0x150 [ 13.683336] ? snd_seq_timer_get_cur_tick+0xd/0x40 [ 13.683912] ? update_timestamp_of_queue+0x14d/0x200 [ 13.684398] snd_seq_deliver_event+0x362/0x820 [ 13.684894] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.685516] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.686515] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.686972] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.687511] dummy_input+0x2c4/0x400 [ 13.688019] ? dummy_free+0x20/0x20 [ 13.688459] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.689004] ? dummy_free+0x20/0x20 [ 13.689411] snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 [ 13.690140] ? snd_seq_ioctl_running_mode+0x150/0x150 [ 13.690724] ? snd_seq_timer_get_cur_tick+0xd/0x40 [ 13.691196] ? update_timestamp_of_queue+0x14d/0x200 [ 13.691731] snd_seq_deliver_event+0x362/0x820 [ 13.692170] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.692793] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.693270] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.693731] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.694241] dummy_input+0x2c4/0x400 [ 13.694606] ? dummy_free+0x20/0x20 [ 13.694955] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.695399] ? dummy_free+0x20/0x20 [ 13.695869] snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 [ 13.696557] ? snd_seq_ioctl_running_mode+0x150/0x150 [ 13.697051] ? snd_seq_timer_get_cur_tick+0xd/0x40 [ 13.697527] ? update_timestamp_of_queue+0x14d/0x200 [ 13.698013] snd_seq_deliver_event+0x362/0x820 [ 13.698460] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.699085] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.699648] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.700203] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.700823] dummy_input+0x2c4/0x400 [ 13.701250] ? dummy_free+0x20/0x20 [ 13.701697] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.702245] ? dummy_free+0x20/0x20 [ 13.702660] snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 [ 13.703385] ? snd_seq_ioctl_running_mode+0x150/0x150 [ 13.704086] ? snd_seq_timer_get_cur_tick+0xd/0x40 [ 13.704739] ? update_timestamp_of_queue+0x14d/0x200 [ 13.705422] snd_seq_deliver_event+0x362/0x820 [ 13.705911] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.706664] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.707301] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.708212] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.708860] dummy_input+0x2c4/0x400 [ 13.709297] ? dummy_free+0x20/0x20 [ 13.709722] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.710240] ? dummy_free+0x20/0x20 [ 13.710652] snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 [ 13.711377] ? snd_seq_ioctl_running_mode+0x150/0x150 [ 13.712020] ? snd_seq_timer_get_cur_tick+0xd/0x40 [ 13.712577] ? update_timestamp_of_queue+0x14d/0x200 [ 13.713102] snd_seq_deliver_event+0x362/0x820 [ 13.713645] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.714409] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.714988] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.715622] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.716271] dummy_input+0x2c4/0x400 [ 13.716737] ? dummy_free+0x20/0x20 [ 13.717168] ? snd_seq_port_use_ptr+0x12d/0x1c0 [ 13.717712] ? dummy_free+0x20/0x20 [ 13.718151] snd_seq_deliver_single_event.constprop.11+0x2fb/0x940 [ 13.718912] ? snd_seq_ioctl_running_mode+0x150/0x150 [ 13.719598] ? snd_seq_client_use_ptr+0x3c/0x330 [ 13.720157] snd_seq_deliver_event+0x176/0x820 [ 13.720669] ? do_raw_spin_trylock+0x190/0x190 [ 13.721200] ? snd_seq_deliver_single_event.constprop.11+0x940/0x940 [ 13.721971] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 13.722569] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.723165] ? trace_hardirqs_on+0xd/0x10 [ 13.723709] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.724290] snd_seq_kernel_client_dispatch+0x11e/0x150 [ 13.724961] snd_seq_oss_midi_reset+0x44b/0x700 [ 13.725528] ? snd_seq_oss_midi_filemode+0xf0/0xf0 [ 13.726137] snd_seq_oss_synth_reset+0x398/0x980 [ 13.726736] ? locks_remove_file+0x3fa/0x5a0 [ 13.727288] ? snd_seq_oss_synth_cleanup+0x400/0x400 [ 13.732149] snd_seq_oss_reset+0x6c/0x260 [ 13.732579] ? free_info_entries+0x36/0x36 [ 13.733006] snd_seq_oss_release+0x71/0x120 [ 13.733438] odev_release+0x52/0x70 [ 13.733800] __fput+0x333/0x7f0 [ 13.734119] ? fput+0x140/0x140 [ 13.734437] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 13.735009] ? _raw_spin_unlock_irq+0x27/0x70 [ 13.735440] ____fput+0x15/0x20 [ 13.739837] task_work_run+0x199/0x270 [ 13.740209] ? task_work_cancel+0x210/0x210 [ 13.743277] ? _raw_spin_unlock+0x22/0x30 [ 13.743775] ? switch_task_namespaces+0x87/0xc0 [ 13.744297] do_exit+0x9b5/0x1ad0 [ 13.744696] ? snd_seq_client_use_ptr+0x85/0x330 [ 13.745237] ? mm_update_next_owner+0x930/0x930 [ 13.745774] ? snd_seq_system_notify+0x11b/0x160 [ 13.746222] ? snd_seq_client_notify_subscription+0x16f/0x210 [ 13.746747] ? snd_seq_dispatch_event+0x5b0/0x5b0 [ 13.747148] ? check_subscription_permission.isra.3+0x11d/0x1d0 [ 13.748194] ? snd_seq_ioctl_subscribe_port+0x1e3/0x2c0 [ 13.748857] ? kasan_check_write+0x14/0x20 [ 13.749364] ? snd_seq_ioctl_unsubscribe_port+0x2c0/0x2c0 [ 13.750847] ? snd_seq_ioctl+0x126/0x400 [ 13.751313] ? snd_seq_open+0x570/0x570 [ 13.751778] ? snd_seq_open+0x570/0x570 [ 13.752202] ? do_vfs_ioctl+0x492/0x1530 [ 13.752679] ? _cond_resched+0x14/0x30 [ 13.753154] ? ioctl_preallocate+0x2b0/0x2b0 [ 13.753673] ? selinux_capable+0x40/0x40 [ 13.754155] ? putname+0xf3/0x130 [ 13.754579] do_group_exit+0x149/0x400 [ 13.755045] ? SyS_exit+0x30/0x30 [ 13.755577] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 13.756221] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 13.756821] SyS_exit_group+0x1d/0x20 [ 13.757274] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 13.757875] RIP: 0033:0x437dd9 [ 13.758278] RSP: 002b:00007ffe20d04a08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 13.759074] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000437dd9 [ 13.759741] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 13.760349] RBP: 0000000000000086 R08: 000000000000003c R09: 00000000000000e7 [ 13.760966] R10: ffffffffffffffc0 R11: 0000000000000246 R12: 0000000000000000 [ 13.761592] R13: 0000000000401e90 R14: 0000000000401f20 R15: 0000000000000000