INFO: rcu_sched self-detected stall on CPU
	1-....: (124999 ticks this GP) idle=6b6/1/4611686018427387906 softirq=35577/35578 fqs=31227 
	 (t=125000 jiffies g=15763 c=15762 q=605)
NMI backtrace for cpu 1
CPU: 1 PID: 12223 Comm: syz-executor5 Not tainted 4.16.0-rc5+ #262
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x123/0x180 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:156 [inline]
 rcu_dump_cpu_stacks+0x186/0x1de kernel/rcu/tree.c:1375
 print_cpu_stall kernel/rcu/tree.c:1524 [inline]
 check_cpu_stall.isra.61+0xbb8/0x15b0 kernel/rcu/tree.c:1592
 __rcu_pending kernel/rcu/tree.c:3361 [inline]
 rcu_pending kernel/rcu/tree.c:3423 [inline]
 rcu_check_callbacks+0x238/0xd20 kernel/rcu/tree.c:2763
 update_process_times+0x30/0x60 kernel/time/timer.c:1636
 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162
 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1194
 __run_hrtimer kernel/time/hrtimer.c:1349 [inline]
 __hrtimer_run_queues+0x39c/0xec0 kernel/time/hrtimer.c:1411
 hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857
 </IRQ>
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xa/0x50 kernel/kcov.c:100
RSP: 0018:ffff8801b2d5fbc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff12
RAX: ffff8801bc7ee340 RBX: dffffc0000000000 RCX: ffffffff839adeef
RDX: 0000000000006000 RSI: ffffc900028d9000 RDI: ffff8801c8e6d938
RBP: ffff8801b2d5fc50 R08: 0000000000000000 R09: 1ffff100365abf2c
R10: ffff8801b2d5f928 R11: 0000000000000001 R12: ffff8801c7a203d8
R13: ffff8801d44a6dc0 R14: ffff8801c7a20840 R15: ffff8801d44a6f10
 lo_compat_ioctl+0xab/0x140 drivers/block/loop.c:1556
 compat_blkdev_ioctl+0x3ae/0x1840 block/compat_ioctl.c:406
 C_SYSC_ioctl fs/compat_ioctl.c:1461 [inline]
 compat_SyS_ioctl+0x151/0x2a30 fs/compat_ioctl.c:1407
 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fa6c99
RSP: 002b:00000000f77a209c EFLAGS: 00000286 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000016 RCX: 0000000000004c00
RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000