rcu: INFO: rcu_sched self-detected stall on CPU rcu: 0-....: (10500 ticks this GP) idle=7ca/1/0x4000000000000002 softirq=106403/106403 fqs=5250 (t=10502 jiffies g=176597 q=1378) NMI backtrace for cpu 0 CPU: 0 PID: 16454 Comm: syz-executor.3 Not tainted 5.2.0+ #71 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+0x16f/0x1f0 /lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 /lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x22d/0x25c /lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 /arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace /./include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf /kernel/rcu/tree_stall.h:254 print_cpu_stall /kernel/rcu/tree_stall.h:455 [inline] check_cpu_stall /kernel/rcu/tree_stall.h:529 [inline] rcu_pending /kernel/rcu/tree.c:2736 [inline] rcu_sched_clock_irq.cold+0x491/0x8c0 /kernel/rcu/tree.c:2183 update_process_times+0x32/0x80 /kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 /kernel/time/tick-sched.c:167 tick_sched_timer+0x47/0x130 /kernel/time/tick-sched.c:1296 __run_hrtimer /kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xd90 /kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x2ea/0x730 /kernel/time/hrtimer.c:1509 local_apic_timer_interrupt /arch/x86/kernel/apic/apic.c:1068 [inline] smp_apic_timer_interrupt+0x10b/0x550 /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:768 [inline] RIP: 0010:__raw_spin_unlock_irqrestore /./include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x91/0xd0 /kernel/locking/spinlock.c:191 Code: 48 c7 c0 90 e3 d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 32 48 83 3d 46 64 a0 01 00 74 16 48 89 df 57 9d <0f> 1f 44 00 00 65 ff 0d 2b 7e cf 78 5b 41 5c 5d c3 0f 0b 0f 0b 48 RSP: 0018:ffff88805e4879d8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a5c72 RBX: 0000000000000282 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282 RBP: ffff88805e4879e8 R08: 1ffffffff14a6d5e R09: fffffbfff14a6d5f R10: fffffbfff14a6d5e R11: ffffffff8a536af7 R12: ffff88809eb29580 R13: ffff88809eb29514 R14: 0000000000000000 R15: ffff88809eb29580 spin_unlock_irqrestore /./include/linux/spinlock.h:393 [inline] snd_seq_cell_free+0x216/0x410 /sound/core/seq/seq_memory.c:200 snd_seq_dispatch_event+0x13c/0x5b0 /sound/core/seq/seq_clientmgr.c:914 snd_seq_check_queue.part.0+0x139/0x360 /sound/core/seq/seq_queue.c:262 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+0xfd/0x6a0 /arch/x86/entry/common.c:296 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:00007fd96ff8ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829 RDX: 00000000ffffff76 RSI: 0000000020000000 RDI: 0000000000000008 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd96ff8f6d4 R13: 00000000004c98c0 R14: 00000000004e0d38 R15: 00000000ffffffff