INFO: task syz-executor.4:4476 can't die for more than 143 seconds. syz-executor.4 R running task 26392 4476 9056 0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/1053: #0: 00000000bb1aeb75 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5257 2 locks held by getty/9001: #0: 00000000b977bef6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007d862e3e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9002: #0: 00000000fc473b78 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005c23d04c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9003: #0: 0000000021bd35c4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007f7605be (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9004: #0: 00000000656636b8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000440bf109 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9005: #0: 00000000dc74f3bc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000029b199aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9006: #0: 0000000035158e0c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000840e7195 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9007: #0: 00000000ca1e1d7e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008c444ab2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.4/4476: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1053 Comm: khungtaskd Not tainted 5.3.0-rc1-next-20190725 #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+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: 1.046 msecs NMI backtrace for cpu 0 CPU: 0 PID: 4476 Comm: syz-executor.4 Not tainted 5.3.0-rc1-next-20190725 #51 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x1a/0x20 kernel/kcov.c:177 Code: 8b 4d 08 e8 18 ff ff ff 5d c3 66 0f 1f 44 00 00 55 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 48 89 e5 48 8b 4d 08 e8 f6 fe ff ff <5d> c3 0f 1f 40 00 55 0f b7 d6 0f b7 f7 bf 03 00 00 00 48 89 e5 48 RSP: 0018:ffff8880ae8096b0 EFLAGS: 00000006 RAX: 0000000080010001 RBX: 0000000000000001 RCX: ffffffff818c3343 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880ae8096b0 R08: ffff8880a7c58380 R09: ffffed1015d06c9c R10: ffffed1015d06c9b R11: ffff8880ae8364db R12: 0000000000000000 R13: 0000000000000001 R14: ffff8880ae809a58 R15: ffff888064c0fa08 FS: 00007f8dde44a700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000095b4a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:642 [inline] __perf_output_begin kernel/events/ring_buffer.c:260 [inline] perf_output_begin_forward+0x843/0xb00 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 f2 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 22 4a 98 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 4c 24 14 fa 65 8b 05 8d 55 c7 78 RSP: 0018:ffff888064c0fab0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a5e50 RBX: 0000000000000282 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282 RBP: ffff888064c0fac0 R08: 1ffffffff14a8357 R09: fffffbfff14a8358 R10: fffffbfff14a8357 R11: ffffffff8a541abf R12: ffff8880a07cd018 R13: ffff88806715bd0c R14: 0000000000000282 R15: ffff8880a07cd018 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] snd_seq_prioq_cell_out+0x1e3/0x350 sound/core/seq/seq_prioq.c:238 snd_seq_check_queue.part.0+0x1a7/0x360 sound/core/seq/seq_queue.c:267 snd_seq_check_queue sound/core/seq/seq_queue.c:242 [inline] snd_seq_enqueue_event+0x1fb/0x4c0 sound/core/seq/seq_queue.c:330 snd_seq_client_enqueue_event.constprop.0+0x259/0x470 sound/core/seq/seq_clientmgr.c:974 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:00007f8dde449c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8dde44a6d4 R13: 00000000004c98c0 R14: 00000000004e0d38 R15: 00000000ffffffff