Buffer I/O error on dev loop0, logical block 8176, async page read INFO: rcu_preempt self-detected stall on CPU 0-...: (1 GPs behind) idle=25b/140000000000001/0 softirq=12446/12448 fqs=6247 (t=12500 jiffies g=2836 c=2835 q=56) Task dump for CPU 0: syz-executor1 R running task 28856 8927 3849 0x0000000c ffff8801db207c18 ffffffff814225a9 ffff8801db221b80 0000000000000000 dffffc0000000000 ffffffff844e0300 ffffffff844e0304 ffff8801db207c38 ffffffff814228cd ffffffff844e0280 0000000000000000 ffff8801db207ca0 Call Trace: [ 281.306841] [] sched_show_task.cold.127+0x1c9/0x279 kernel/sched/core.c:5321 [] dump_cpu_task+0x79/0x7e kernel/sched/core.c:9046 [] rcu_dump_cpu_stacks+0x191/0x1c1 kernel/rcu/tree.c:1303 [] print_cpu_stall kernel/rcu/tree.c:1446 [inline] [] check_cpu_stall kernel/rcu/tree.c:1514 [inline] [] __rcu_pending kernel/rcu/tree.c:3487 [inline] [] rcu_pending kernel/rcu/tree.c:3551 [inline] [] rcu_check_callbacks.cold.79+0x43a/0xd27 kernel/rcu/tree.c:2880 [] update_process_times+0x30/0x70 kernel/time/timer.c:1629 [] tick_sched_handle.isra.14+0x55/0xf0 kernel/time/tick-sched.c:151 [] tick_sched_timer+0x72/0x120 kernel/time/tick-sched.c:1190 [] __run_hrtimer kernel/time/hrtimer.c:1255 [inline] [] __hrtimer_run_queues+0x375/0xe50 kernel/time/hrtimer.c:1319 [] hrtimer_interrupt+0x1b1/0x430 kernel/time/hrtimer.c:1353 [] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:935 [] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:959 [] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648 [ 281.416671] [] ? do_make_slave fs/pnode.c:84 [inline] [ 281.416671] [] ? change_mnt_propagation+0x88/0xbd0 fs/pnode.c:130 [] umount_tree+0x326/0x820 fs/namespace.c:1515 [] attach_recursive_mnt+0x750/0x8f0 fs/namespace.c:2057 [] graft_tree+0x16f/0x1f0 fs/namespace.c:2121 [] do_loopback fs/namespace.c:2242 [inline] [] do_mount+0x1f5f/0x2740 fs/namespace.c:2828 [] SYSC_mount fs/namespace.c:3050 [inline] [] SyS_mount+0xfe/0x110 fs/namespace.c:3027 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb