syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/2:b..l
	(detected by 1, t=10502 jiffies, g=5425, q=49639 ncpus=2)
task:kworker/u4:0    state:R  running task     stack:0     pid:9     ppid:2      flags:0x00000008
Workqueue: netns cleanup_net
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6558
 preempt_schedule_irq+0x8c/0x1b8 kernel/sched/core.c:6870
 arm64_preempt_schedule_irq arch/arm64/kernel/entry-common.c:265 [inline]
 __el1_irq arch/arm64/kernel/entry-common.c:474 [inline]
 el1_interrupt+0x4c/0x68 arch/arm64/kernel/entry-common.c:486
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581
 arch_local_irq_restore+0x8/0x10 arch/arm64/include/asm/irqflags.h:122
 lock_is_held include/linux/lockdep.h:283 [inline]
 rcu_read_lock_held+0x34/0x50 kernel/rcu/update.c:311
 xa_entry include/linux/xarray.h:1198 [inline]
 xas_find_marked+0x7dc/0xe84 lib/xarray.c:1349
 xa_find+0x238/0x3c8 lib/xarray.c:2022
 devlinks_xa_find_get+0xfc/0x2dc net/devlink/leftover.c:300
 devlinks_xa_find_get_first net/devlink/leftover.c:328 [inline]
 devlink_pernet_pre_exit+0xc8/0x2fc net/devlink/leftover.c:12518
 ops_pre_exit_list net/core/net_namespace.c:162 [inline]
 cleanup_net+0x488/0x994 net/core/net_namespace.c:592
 process_one_work+0x7ac/0x1404 kernel/workqueue.c:2292
 worker_thread+0x8e4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864