rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P601/1:b..l
	(detected by 0, t=10502 jiffies, g=10369, q=438)
task:kworker/u4:5    state:R  running task     stack:    0 pid:  601 ppid:     2 flags:0x00000008
Workqueue: netns cleanup_net
Call trace:
 __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:521
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xe00/0x1c0c kernel/sched/core.c:6376
 preempt_schedule_irq+0x90/0x214 kernel/sched/core.c:6780
 arm64_preempt_schedule_irq+0x14c/0x21c arch/arm64/kernel/entry-common.c:260
 el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:463
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470
 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
 lock_acquire+0x234/0x620 kernel/locking/lockdep.c:5626
 rcu_lock_acquire+0x40/0x4c include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 inet_twsk_purge+0x10c/0x7ac net/ipv4/inet_timewait_sock.c:268
 dccp_v4_exit_batch+0x20/0x2c net/dccp/ipv4.c:1040
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x644/0xa98 net/core/net_namespace.c:635
 process_one_work+0x79c/0x1140 kernel/workqueue.c:2310
 worker_thread+0x8f4/0x101c kernel/workqueue.c:2457
 kthread+0x374/0x454 kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: rcu_preempt kthread starved for 10494 jiffies! g10369 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:    0 pid:   15 ppid:     2 flags:0x00000008
Call trace:
 __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:521
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xe00/0x1c0c kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 schedule_timeout+0x180/0x2c8 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x25c/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xc4/0x2a8 kernel/rcu/tree.c:2145
 kthread+0x374/0x454 kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 1:
task:syz.0.20        state:R  running task     stack:    0 pid: 4974 ppid:  4766 flags:0x00000001
Call trace:
 __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:521
 0xffff0000cb674058