rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 ticks this GP) idle=e16/1/0x4000000000000004 softirq=117536/117536 fqs=0 
	(t=29986 jiffies g=186969 q=3462)
rcu: rcu_preempt kthread starved for 29986 jiffies! g186969 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29112    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3252 [inline]
 __schedule+0x755/0x1580 kernel/sched/core.c:3878
 schedule+0xa8/0x270 kernel/sched/core.c:3942
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807
 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline]
 rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:353
NMI backtrace for cpu 1
CPU: 1 PID: 22113 Comm: syz-executor.2 Not tainted 5.2.0-rc6-next-20190628 #25
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+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_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+0x4dd/0xc13 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+0x53/0x140 kernel/time/tick-sched.c:1296
 __run_hrtimer kernel/time/hrtimer.c:1388 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1450
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1508
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1066
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
RIP: 0010:ffs arch/x86/include/asm/bitops.h:298 [inline]
RIP: 0010:__do_softirq+0x227/0x98c kernel/softirq.c:280
Code: c7 c0 40 ea d2 88 48 c1 e8 03 42 80 3c 30 00 0f 85 b1 06 00 00 48 83 3d 26 e8 72 01 00 0f 84 d6 05 00 00 fb 66 0f 1f 44 00 00 <b8> ff ff ff ff 48 c7 45 c8 00 91 c0 88 0f bc 45 d4 83 c0 01 89 45
RSP: 0018:ffff8880ae909f18 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5d48 RBX: ffff888056286180 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffff888056286a40 RDI: ffff888056286a14
RBP: ffff8880ae909f98 R08: 1ffffffff14a3758 R09: fffffbfff14a3759
R10: fffffbfff14a3758 R11: ffffffff8a51bac7 R12: ffff88805bd77948
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:535 [inline]
 do_IRQ+0x12c/0x200 arch/x86/kernel/irq.c:259
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:584
 </IRQ>
RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x50 kernel/kcov.c:107
Code: a0 8f 7e 81 e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 f8 12 00 00 83 fa 02 75 20 48 8b 88 00 13 00 00 8b 80 fc 12 00 00 48 8b 11 <48> 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65
RSP: 0018:ffff88805bd779f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffde
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc9000a21b000
RDX: 000000000003ffff RSI: ffffffff810cfb8c RDI: 0000000000000001
RBP: ffff88805bd779f0 R08: ffff888056286180 R09: fffffbfff14a3759
R10: ffff88805bd77b30 R11: ffff888056286180 R12: ffff88808c052240
R13: 0000000000000000 R14: ffffc90009fc0db8 R15: ffff88808c052240
 __read_once_size include/linux/compiler.h:194 [inline]
 kvm_request_pending include/linux/kvm_host.h:1200 [inline]
 vcpu_enter_guest+0xec/0x5d90 arch/x86/kvm/x86.c:7759
 vcpu_run arch/x86/kvm/x86.c:8096 [inline]
 kvm_arch_vcpu_ioctl_run+0x463/0x1790 arch/x86/kvm/x86.c:8304
 kvm_vcpu_ioctl+0x4dc/0xfc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2752
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459519
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:00007fb0ba486c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459519
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb0ba4876d4
R13: 00000000004c284e R14: 00000000004d5af8 R15: 00000000ffffffff