Buffer I/O error on dev loop0, logical block 0, async page read
INFO: rcu_sched self-detected stall on CPU
	0-...: (124985 ticks this GP) idle=f02/140000000000001/0 softirq=29867/29867 fqs=31222 
	 (t=125000 jiffies g=16344 c=16343 q=489)
NMI backtrace for cpu 0
CPU: 0 PID: 9113 Comm: syz-executor4 Not tainted 4.14.0-rc5+ #140
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 nmi_cpu_backtrace+0x20e/0x240 lib/nmi_backtrace.c:102
 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:61
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 trigger_single_cpu_backtrace include/linux/nmi.h:155 [inline]
 rcu_dump_cpu_stacks+0x180/0x1d6 kernel/rcu/tree.c:1396
 print_cpu_stall kernel/rcu/tree.c:1542 [inline]
 check_cpu_stall.isra.64+0xaae/0x1480 kernel/rcu/tree.c:1610
 __rcu_pending kernel/rcu/tree.c:3373 [inline]
 rcu_pending kernel/rcu/tree.c:3435 [inline]
 rcu_check_callbacks+0x256/0xce0 kernel/rcu/tree.c:2775
 update_process_times+0x30/0x60 kernel/time/timer.c:1590
 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:161
 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1190
 __run_hrtimer kernel/time/hrtimer.c:1213 [inline]
 __hrtimer_run_queues+0x349/0xe10 kernel/time/hrtimer.c:1277
 hrtimer_interrupt+0x1c2/0x5e0 kernel/time/hrtimer.c:1311
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
 smp_apic_timer_interrupt+0x156/0x710 arch/x86/kernel/apic/apic.c:1057
 apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:770
 </IRQ>
RIP: 0010:is_loop_device drivers/block/loop.c:686 [inline]
RIP: 0010:loop_set_fd drivers/block/loop.c:874 [inline]
RIP: 0010:lo_ioctl+0x547/0x1b70 drivers/block/loop.c:1353
RSP: 0018:ffff8801ca817958 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000010000 RBX: dffffc0000000000 RCX: ffffc90001322000
RDX: 0000000000000000 RSI: ffffffff8355ea3f RDI: ffff8801c2100eb8
RBP: ffff8801ca8179d0 R08: 0000000000000001 R09: 1ffff10039502edc
R10: ffff8801ca8176a8 R11: 0000000000000001 R12: ffff8801d11b4998
R13: ffff8801d5c4e000 R14: ffff8801d1199140 R15: ffff8801d5c4e150
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0xc07/0x1de0 block/ioctl.c:594
 block_ioctl+0xde/0x120 fs/block_dev.c:1872
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 do_syscall_64+0x26c/0x8d0 arch/x86/entry/common.c:287
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x452719
RSP: 002b:00007fe72ac51be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452719
RDX: 0000000000000013 RSI: 0000000000004c00 RDI: 0000000000000015
RBP: 000000000000028b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f1da8
R13: 00000000ffffffff R14: 00007fe72ac526d4 R15: 0000000000000000