INFO: rcu_preempt self-detected stall on CPU 1-...: (1 GPs behind) idle=231/140000000000001/0 softirq=113936/113938 fqs=5233 (t=10500 jiffies g=15050 c=15049 q=16) Task dump for CPU 1: syz-executor2 R running task 28936 28529 3849 0x2002000c ffff8801db307c18 ffffffff814247b9 ffff8801db321c00 0000000000000001 dffffc0000000000 ffffffff846e0380 ffffffff846e0384 ffff8801db307c38 ffffffff81424add ffffffff846e0300 0000000000000001 ffff8801db307ca0 Call Trace: <IRQ> [ 735.364208] [<ffffffff814247b9>] sched_show_task.cold.127+0x1c9/0x279 kernel/sched/core.c:5321 [<ffffffff81424add>] dump_cpu_task+0x79/0x7e kernel/sched/core.c:9046 [<ffffffff8142ecaa>] rcu_dump_cpu_stacks+0x191/0x1c1 kernel/rcu/tree.c:1303 [<ffffffff8142f8e6>] print_cpu_stall kernel/rcu/tree.c:1446 [inline] [<ffffffff8142f8e6>] check_cpu_stall kernel/rcu/tree.c:1514 [inline] [<ffffffff8142f8e6>] __rcu_pending kernel/rcu/tree.c:3487 [inline] [<ffffffff8142f8e6>] rcu_pending kernel/rcu/tree.c:3551 [inline] [<ffffffff8142f8e6>] rcu_check_callbacks.cold.79+0x43a/0xd27 kernel/rcu/tree.c:2880 [<ffffffff812a0ac0>] update_process_times+0x30/0x70 kernel/time/timer.c:1629 [<ffffffff812cc695>] tick_sched_handle.isra.14+0x55/0xf0 kernel/time/tick-sched.c:151 [<ffffffff812cceb2>] tick_sched_timer+0x72/0x120 kernel/time/tick-sched.c:1190 [<ffffffff812a4775>] __run_hrtimer kernel/time/hrtimer.c:1255 [inline] [<ffffffff812a4775>] __hrtimer_run_queues+0x375/0xe50 kernel/time/hrtimer.c:1319 [<ffffffff812a5cb1>] hrtimer_interrupt+0x1b1/0x430 kernel/time/hrtimer.c:1353 [<ffffffff810b2384>] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:935 [<ffffffff839ff71c>] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:959 [<ffffffff839fb8b0>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648 <EOI> [ 735.473565] [<ffffffff8160fc68>] ? do_make_slave fs/pnode.c:84 [inline] <EOI> [ 735.473565] [<ffffffff8160fc68>] ? change_mnt_propagation+0x88/0xbd0 fs/pnode.c:130 [<ffffffff815dc056>] umount_tree+0x326/0x820 fs/namespace.c:1516 [<ffffffff815e4260>] attach_recursive_mnt+0x750/0x8f0 fs/namespace.c:2058 [<ffffffff815e456f>] graft_tree+0x16f/0x1f0 fs/namespace.c:2122 [<ffffffff815e6f2f>] do_loopback fs/namespace.c:2243 [inline] [<ffffffff815e6f2f>] do_mount+0x1f5f/0x2740 fs/namespace.c:2829 [<ffffffff8168c46c>] C_SYSC_mount fs/compat.c:810 [inline] [<ffffffff8168c46c>] compat_SyS_mount+0x4fc/0xff0 fs/compat.c:775 [<ffffffff81006da7>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline] [<ffffffff81006da7>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387 [<ffffffff839fb650>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137