rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=2ee/1/0x4000000000000002 softirq=100170/100172 fqs=29 
rcu: 	 (t=10501 jiffies g=88833 q=739)
rcu: rcu_preempt kthread starved for 10444 jiffies! g88833 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29168    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2877 [inline]
 __schedule+0x813/0x1cc0 kernel/sched/core.c:3518
 schedule+0x92/0x180 kernel/sched/core.c:3562
 schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803
 rcu_gp_fqs_loop kernel/rcu/tree.c:1971 [inline]
 rcu_gp_kthread+0x962/0x17b0 kernel/rcu/tree.c:2128
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 6422 Comm: syz-executor.3 Not tainted 5.1.0-rc5+ #71
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+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 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.c:1223
 print_cpu_stall kernel/rcu/tree.c:1360 [inline]
 check_cpu_stall kernel/rcu/tree.c:1434 [inline]
 rcu_pending kernel/rcu/tree.c:3103 [inline]
 rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x3/0x20 kernel/kcov.c:189
Code: ff 5d c3 0f 1f 40 00 55 0f b7 d6 0f b7 f7 bf 03 00 00 00 48 89 e5 48 8b 4d 08 e8 d8 fe ff ff 5d c3 66 0f 1f 44 00 00 55 89 f2 <89> fe bf 05 00 00 00 48 89 e5 48 8b 4d 08 e8 ba fe ff ff 5d c3 0f
RSP: 0018:ffff888063f9f950 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff888063f9faa0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888063f9fa30 R08: ffff8880933a2080 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00007fcd2c5dea08
R13: dffffc0000000000 R14: ffff888063f9fb68 R15: 0000000000000000
 futex_wait+0x1fc/0x5e0 kernel/futex.c:2704
 do_futex+0x170/0x1df0 kernel/futex.c:3604
 __do_sys_futex kernel/futex.c:3665 [inline]
 __se_sys_futex kernel/futex.c:3633 [inline]
 __x64_sys_futex+0x3f7/0x590 kernel/futex.c:3633
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b89f
Code: 89 d8 83 e0 0c 83 f8 04 74 01 c3 64 48 8b 3c 25 00 00 00 00 b8 ca 00 00 00 4d 31 d2 48 81 c7 08 03 00 00 be 80 00 00 00 0f 05 <64> 8b 04 25 08 03 00 00 eb ce 0f 1f 80 00 00 00 00 48 83 ec 08 48
RSP: 002b:00007fcd2c5de168 EFLAGS: 00000202 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fcd2c5de2e0 RCX: 000000000045b89f
RDX: 000000000000000b RSI: 0000000000000080 RDI: 00007fcd2c5dea08
RBP: 0000000000000010 R08: 00000000004f2200 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000020
R13: 0000000000000003 R14: 00007fcd2c5de1d0 R15: 0000000000000002