rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5088/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=54993, q=329 ncpus=2)
task:syz-executor    state:R  running task     stack:22592 pid:5088  tgid:5088  ppid:5082   flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5407 [inline]
 __schedule+0xf27/0x5d10 kernel/sched/core.c:6748
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7070
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:handle_dots+0x21/0x1740 fs/namei.c:1985
Code: 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 48 8d 85 50 ff ff ff 41 56 48 c1 e8 03 41 55 41 54 49 bc 00 00 00 00 00 fc ff df <41> 52 53 89 f3 48 81 ec b8 00 00 00 48 89 85 38 ff ff ff 4c 01 e0
RSP: 0018:ffffc9000326fb48 EFLAGS: 00000a02
RAX: 1ffff9200064df57 RBX: 0000000000000002 RCX: ffffffff81fe1083
RDX: ffff88806639bc00 RSI: 0000000000000002 RDI: ffffc9000326fce0
RBP: ffffc9000326fb68 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffc9000326fd30 R14: ffffc9000326fce0 R15: ffff88807bdb0022
 walk_component+0x2b2/0x5b0 fs/namei.c:2033
 link_path_walk.part.0.constprop.0+0x669/0xd40 fs/namei.c:2404
 link_path_walk fs/namei.c:2335 [inline]
 path_lookupat+0x93/0x770 fs/namei.c:2565
 filename_lookup+0x1e5/0x5b0 fs/namei.c:2595
 user_path_at+0x3a/0x60 fs/namei.c:3002
 ksys_umount fs/namespace.c:2033 [inline]
 __do_sys_umount fs/namespace.c:2041 [inline]
 __se_sys_umount fs/namespace.c:2039 [inline]
 __x64_sys_umount+0x10b/0x1a0 fs/namespace.c:2039
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd81bb76d47
RSP: 002b:00007ffdd3d6e518 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd81bb76d47
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdd3d6e5d0
RBP: 00007ffdd3d6e5d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdd3d6f690
R13: 00007fd81bbe3515 R14: 000000000009015f R15: 000000000008fc68
 </TASK>
rcu: rcu_preempt kthread starved for 10523 jiffies! g54993 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27872 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5407 [inline]
 __schedule+0xf27/0x5d10 kernel/sched/core.c:6748
 __schedule_loop kernel/sched/core.c:6825 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6840
 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111