INFO: rcu_sched self-detected stall on CPU 0-....: (1 GPs behind) idle=23e/1/4611686018427387906 softirq=85459/85460 fqs=31222 (t=125000 jiffies g=38835 c=38834 q=332) NMI backtrace for cpu 0 CPU: 0 PID: 27381 Comm: syz-executor1 Not tainted 4.16.0-rc6+ #270 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __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 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 RSP: 0018:ffff8801b3367bd0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff12 RAX: 0000000000010000 RBX: dffffc0000000000 RCX: ffffffff839af6d2 RDX: 1ffff10038dc498c RSI: ffffc900018a0000 RDI: ffff8801add566f8 RBP: ffff8801b3367c50 R08: 0000000000000000 R09: 1ffff1003666cf2c R10: ffff8801b3367928 R11: 0000000000000001 R12: ffff8801c6e24a58 R13: ffff8801d45c0900 R14: ffff8801c6df9780 R15: ffff8801d45c0a50 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: 0023:0xf7f3fc99 RSP: 002b:00000000f773b09c EFLAGS: 00000286 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000014 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