INFO: task syz-executor4:10074 blocked for more than 140 seconds. Not tainted 4.19.0-rc1-next-20180829+ #51 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D25408 10074 4688 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3575 __mutex_lock_common kernel/locking/mutex.c:1003 [inline] __mutex_lock+0xbf9/0x1700 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007fc4acea8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc4acea96d4 RCX: 0000000000457089 RDX: 00000000200000c0 RSI: 00000000c08c5332 RDI: 0000000000000004 RBP: 00000000009303c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d03b8 R14: 00000000004bf0e0 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/792: #0: 00000000d99d04d6 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/4546: 2 locks held by getty/4636: #0: 00000000305d79e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a40fde57 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4637: #0: 00000000c388f506 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000037725fab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4638: #0: 000000007b30a19f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000eeabd25e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4639: #0: 000000002450a47a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000397e07ae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4640: #0: 00000000888b893e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b80aeebb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4641: #0: 0000000083c7c198 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ed6b53af (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4642: #0: 00000000533c5e81 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d3442a67 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by kworker/1:5/8467: #0: 00000000ec5a99f7 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000ec5a99f7 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000ec5a99f7 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000ec5a99f7 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000ec5a99f7 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000ec5a99f7 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000ec5a99f7 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 0000000028711622 (key_gc_work){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 1 lock held by syz-executor4/10059: 1 lock held by syz-executor4/10074: #0: 00000000fe88235b (&client->ioctl_mutex){+.+.}, at: snd_seq_ioctl+0x221/0x440 sound/core/seq/seq_clientmgr.c:2137 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 792 Comm: khungtaskd Not tainted 4.19.0-rc1-next-20180829+ #51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x1040 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.369 msecs NMI backtrace for cpu 0 CPU: 0 PID: 10059 Comm: syz-executor4 Not tainted 4.19.0-rc1-next-20180829+ #51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xea/0x5020 kernel/locking/lockdep.c:3271 Code: c7 40 2c f2 f2 f2 f2 c7 40 30 00 f2 f2 f2 c7 40 34 f2 f2 f2 f2 c7 40 38 00 f2 f2 f2 c7 40 3c f2 f2 f2 f2 c7 40 40 00 f2 f2 f2 40 44 f2 f2 f2 f2 c7 40 48 00 f2 f2 f2 c7 40 4c f2 f2 f2 f2 c7 RSP: 0018:ffff8801db007820 EFLAGS: 00000086 RAX: ffffed003b600f18 RBX: 1ffff1003b600f80 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff89b5d9c8 RBP: ffff8801db007ba8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffed003b604b98 R11: ffff8801db025cc3 R12: 0000000000000001 R13: ffffffff89b5d9c8 R14: ffff8801cad500c0 R15: 0000000000000002 FS: 00007fc4acf4e700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020c00000 CR3: 00000001c1360000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901 seqcount_lockdep_reader_access include/linux/seqlock.h:81 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] ktime_get_update_offsets_now+0x143/0x5d0 kernel/time/timekeeping.c:2247 hrtimer_update_base kernel/time/hrtimer.c:587 [inline] hrtimer_interrupt+0x111/0x750 kernel/time/hrtimer.c:1500 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1029 [inline] smp_apic_timer_interrupt+0x16d/0x6a0 arch/x86/kernel/apic/apic.c:1054 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:867 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:788 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184 Code: 68 be 11 88 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 21 48 83 3d ce 41 3b 01 00 74 0e 48 89 df 57 9d <0f> 1f 44 00 00 eb bb 0f 0b 0f 0b e8 3f 5c e5 fa eb 97 e8 38 5c e5 RSP: 0018:ffff880194b77520 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 1ffff100395aa124 RDX: 1ffffffff10237cd RSI: 0000000000000000 RDI: 0000000000000286 RBP: ffff880194b77530 R08: ffff8801cad50900 R09: 0000000000000006 R10: ffff8801cad500c0 R11: 0000000000000000 R12: ffffffff88865680 R13: 0000000000000286 R14: ffffffff8519e5a0 R15: ffffc90001b9a8ae spin_unlock_irqrestore include/linux/spinlock.h:384 [inline] queueptr+0x99/0xb0 sound/core/seq/seq_queue.c:227 snd_seq_control_queue+0x64/0x680 sound/core/seq/seq_queue.c:727 event_input_timer+0x25/0x30 sound/core/seq/seq_system.c:118 snd_seq_deliver_single_event.constprop.15+0x89a/0xa20 sound/core/seq/seq_clientmgr.c:621 snd_seq_deliver_event+0x5a4/0x950 sound/core/seq/seq_clientmgr.c:822 snd_seq_dispatch_event+0x12c/0x650 sound/core/seq/seq_clientmgr.c:896 snd_seq_check_queue.part.4+0x139/0x360 sound/core/seq/seq_queue.c:275 snd_seq_check_queue sound/core/seq/seq_queue.c:255 [inline] snd_seq_enqueue_event+0x346/0x4d0 sound/core/seq/seq_queue.c:343 snd_seq_client_enqueue_event+0x2a5/0x510 sound/core/seq/seq_clientmgr.c:957 snd_seq_write+0x3f1/0x8d0 sound/core/seq/seq_clientmgr.c:1074 __vfs_write+0x117/0x9d0 fs/read_write.c:485 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc4acf4dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc4acf4e6d4 RCX: 0000000000457089 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d7cc0 R14: 00000000004caaa4 R15: 0000000000000000