INFO: rcu_sched self-detected stall on CPU
	1-....: (119999 ticks this GP) idle=76a/1/4611686018427387906 softirq=29825/29825 fqs=29659 
	 (t=120000 jiffies g=17325 c=17324 q=1139)
NMI backtrace for cpu 1
CPU: 1 PID: 7872 Comm: syz-executor3 Not tainted 4.17.0+ #5
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+0x185/0x1d0 lib/dump_stack.c:113
 nmi_cpu_backtrace lib/nmi_backtrace.c:103 [inline]
 nmi_trigger_cpumask_backtrace+0x262/0x4c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x2c/0x40 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
 rcu_dump_cpu_stacks+0x307/0x4b0 kernel/rcu/tree.c:1376
 print_cpu_stall kernel/rcu/tree.c:1525 [inline]
 check_cpu_stall kernel/rcu/tree.c:1593 [inline]
 __rcu_pending kernel/rcu/tree.c:3356 [inline]
 rcu_pending kernel/rcu/tree.c:3401 [inline]
 rcu_check_callbacks+0x11c5/0x2ae0 kernel/rcu/tree.c:2763
 update_process_times+0x132/0x1a0 kernel/time/timer.c:1636
 tick_sched_handle kernel/time/tick-sched.c:164 [inline]
 tick_sched_timer+0x3ba/0x520 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0xc54/0x1630 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x451/0x13c0 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt+0x6b/0x250 arch/x86/kernel/apic/apic.c:1025
 smp_apic_timer_interrupt+0x5a/0x90 arch/x86/kernel/apic/apic.c:1053
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>
RIP: 0010:is_loop_device drivers/block/loop.c:713 [inline]
RIP: 0010:loop_set_fd drivers/block/loop.c:901 [inline]
RIP: 0010:lo_ioctl+0xf95/0x4450 drivers/block/loop.c:1398
RSP: 0018:ffff88012961f870 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 0000000000006000 RCX: ffff880000000000
RDX: ffff8801d9379798 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff88012961fb00 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: ffffffff861c6250 R12: 0000000000000000
R13: 000000000802001d R14: ffff8801db429798 R15: 00000000fffff000
 __blkdev_driver_ioctl block/ioctl.c:303 [inline]
 blkdev_ioctl+0x2290/0x4f80 block/ioctl.c:601
 block_ioctl+0x16f/0x1d0 fs/block_dev.c:1877
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0xcbd/0x24b0 fs/ioctl.c:686
 ksys_ioctl fs/ioctl.c:701 [inline]
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x280/0x320 fs/ioctl.c:706
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4559f9
RSP: 002b:00007f37fbc24c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f37fbc256d4 RCX: 00000000004559f9
RDX: 0000000000000014 RSI: 0000000000004c00 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004bdfa0 R14: 00000000004cbf78 R15: 0000000000000000
random: crng init done