INFO: task syz-executor.0:26812 can't die for more than 143 seconds. syz-executor.0 R running task 26776 26812 9096 0x00004006 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 Showing all locks held in the system: 1 lock held by khungtaskd/1054: #0: 00000000d6b68743 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5257 1 lock held by rsyslogd/8965: #0: 00000000a7d01b8f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/9055: #0: 00000000020a2277 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f2dd7fbc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9056: #0: 00000000a4be395a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c4c3501a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9057: #0: 00000000e535fc9b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000eb015539 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9058: #0: 0000000058ad72d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d701c6bb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9059: #0: 00000000984e247c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000fc4d0842 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9060: #0: 000000008b1fd115 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006d37f92c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9061: #0: 00000000e946a972 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f29e6526 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/26812: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1054 Comm: khungtaskd Not tainted 5.3.0-rc1-next-20190724 #50 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:249 [inline] watchdog+0xc54/0x1320 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.150 msecs NMI backtrace for cpu 0 CPU: 0 PID: 26812 Comm: syz-executor.0 Not tainted 5.3.0-rc1-next-20190724 #50 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_lockdep_rcu_enabled+0x72/0xa0 kernel/rcu/update.c:238 Code: df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 38 d0 7c 04 84 d2 75 23 8b 05 1c 39 46 08 85 c0 74 07 e8 2f ff ff ff 5d 31 c0 5d c3 48 c7 c7 2c 3b a5 89 e8 8d c0 4d 00 eb a9 48 c7 c7 RSP: 0018:ffff8880ae809658 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff134ad86 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8880918e49d4 RBP: ffff8880ae8096a8 R08: 1ffffffff134a748 R09: fffffbfff134a749 R10: fffffbfff134a748 R11: ffffffff89a53a47 R12: ffffffff88dac100 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 FS: 00007fcb6ef2e700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c428e51108 CR3: 00000000923b4000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:592 [inline] __perf_output_begin kernel/events/ring_buffer.c:162 [inline] perf_output_begin_forward+0xd9/0xb00 kernel/events/ring_buffer.c:268 __perf_event_output kernel/events/core.c:6595 [inline] perf_event_output_forward+0x125/0x290 kernel/events/core.c:6613 __perf_event_overflow+0x141/0x370 kernel/events/core.c:8080 perf_swevent_hrtimer+0x279/0x3e0 kernel/events/core.c:9466 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1068 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1093 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x95/0xe0 kernel/locking/spinlock.c:191 Code: 48 c7 c0 80 f1 d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d 52 59 98 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 7c 34 14 fa 65 8b 05 3d 65 c7 78 RSP: 0018:ffff88808fd9f978 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a5e30 RBX: 0000000000000286 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffff88808fd9f988 R08: 1ffffffff14a8159 R09: fffffbfff14a815a R10: fffffbfff14a8159 R11: ffffffff8a540acf R12: ffff8880a99f9180 R13: ffff8880a99f9180 R14: 0000000000000000 R15: ffff888099203840 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] snd_seq_cell_alloc.isra.0+0x35d/0x670 sound/core/seq/seq_memory.c:269 snd_seq_event_dup+0x183/0x990 sound/core/seq/seq_memory.c:298 snd_seq_client_enqueue_event.constprop.0+0x234/0x470 sound/core/seq/seq_clientmgr.c:968 snd_seq_write+0x40b/0x740 sound/core/seq/seq_clientmgr.c:1093 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x220/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: fd b7 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 b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fcb6ef2dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcb6ef2e6d4 R13: 00000000004c98c0 R14: 00000000004e0d38 R15: 00000000ffffffff