rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 	1-....: (10499 ticks this GP) idle=466/1/0x4000000000000002 softirq=139645/139645 fqs=5249 
	(t=10501 jiffies g=217573 q=2147)
NMI backtrace for cpu 1
CPU: 1 PID: 6418 Comm: syz-executor.0 Not tainted 5.2.0+ #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
 nmi_cpu_backtrace+0xb0/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x14c/0x240 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 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+0x7e3/0xfb0 kernel/rcu/tree.c:2183
 update_process_times+0x114/0x170 kernel/time/timer.c:1639
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x257/0x410 kernel/time/tick-sched.c:1296
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x471/0x8c0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x36c/0xd80 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1068 [inline]
 smp_apic_timer_interrupt+0xc2/0x220 arch/x86/kernel/apic/apic.c:1093
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
 </IRQ>
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+0xad/0xd0 kernel/locking/spinlock.c:191
Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 80 87 ca 88 e8 b2 3a 0a fa 48 83 3d 8a a5 23 01 00 74 19 4c 89 f7 57 9d <0f> 1f 44 00 00 65 83 05 42 1b 5b 78 ff 5b 41 5e 5d c3 0f 0b 0f 0b
RSP: 0018:ffff8880872df870 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11950f0 RBX: ffff88809f87ea98 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000282
RBP: ffff8880872df880 R08: ffff8880971aced0 R09: fffffbfff13bc0b7
R10: fffffbfff13bc0b7 R11: 0000000000000000 R12: 0000000000000282
R13: 1ffff11010bda33d R14: 0000000000000282 R15: ffff88809f87ea90
 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline]
 snd_seq_prioq_cell_out+0x297/0x440 sound/core/seq/seq_prioq.c:238
 snd_seq_check_queue+0x13e/0x3b0 sound/core/seq/seq_queue.c:258
 snd_seq_enqueue_event+0x3a1/0x590 sound/core/seq/seq_queue.c:330
 snd_seq_client_enqueue_event+0x316/0x4e0 sound/core/seq/seq_clientmgr.c:974
 snd_seq_write+0x723/0xac0 sound/core/seq/seq_clientmgr.c:1093
 __vfs_write+0xf9/0x7d0 fs/read_write.c:494
 vfs_write+0x275/0x590 fs/read_write.c:558
 ksys_write+0x16b/0x2a0 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+0x7b/0x90 fs/read_write.c:620
 do_syscall_64+0xfe/0x140 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:00007f451e678c78 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: 00007f451e6796d4
R13: 00000000004c98c0 R14: 00000000004e0d38 R15: 00000000ffffffff