rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P39/1:b..l P3843/1:b..l
	(detected by 1, t=10502 jiffies, g=4517, q=202 ncpus=2)
task:udevd           state:R  running task     stack:0     pid:3843  ppid:1      flags:0x00000004
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6561
 preempt_schedule_common+0xf4/0x1e8 kernel/sched/core.c:6730
 preempt_schedule+0x64/0x84 kernel/sched/core.c:6754
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x80/0x84 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 lockref_get_not_dead+0x80/0xd4 lib/lockref.c:190
 __legitimize_path fs/namei.c:708 [inline]
 legitimize_path fs/namei.c:718 [inline]
 legitimize_root fs/namei.c:746 [inline]
 try_to_unlazy+0x210/0x500 fs/namei.c:781
 may_lookup fs/namei.c:1717 [inline]
 link_path_walk+0x24c/0xcc8 fs/namei.c:2267
 path_lookupat+0x90/0x3d0 fs/namei.c:2478
 filename_lookup+0x1d4/0x4e0 fs/namei.c:2508
 vfs_statx+0xf8/0x420 fs/stat.c:229
 vfs_fstatat fs/stat.c:267 [inline]
 __do_sys_newfstatat fs/stat.c:437 [inline]
 __se_sys_newfstatat fs/stat.c:431 [inline]
 __arm64_sys_newfstatat+0x134/0x1c0 fs/stat.c:431
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
task:kworker/u4:2    state:R  running task     stack:0     pid:39    ppid:2      flags:0x00000008
Workqueue: bat_events batadv_nc_worker
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6561
 preempt_schedule_irq+0x8c/0x1b8 kernel/sched/core.c:6873
 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 arch/arm64/include/asm/irqflags.h:122 [inline]
 lock_acquire+0x2ac/0x7cc kernel/locking/lockdep.c:5665
 rcu_lock_acquire+0x40/0x4c include/linux/rcupdate.h:350
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xd0/0x580 net/batman-adv/network-coding.c:719
 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
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g4517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=2503
rcu: rcu_preempt kthread starved for 10506 jiffies! g4517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:0     pid:16    ppid:2      flags:0x00000008
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0xef4/0x1d44 kernel/sched/core.c:6561
 schedule+0xc4/0x170 kernel/sched/core.c:6637
 schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2cc/0x1538 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xc0/0x308 kernel/rcu/tree.c:1905
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 0:
task:syz.2.3         state:R  running task     stack:0     pid:4333  ppid:4228   flags:0x00000001
Call trace:
 __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
 0xffff0000da08a638
vkms_vblank_simulate: vblank timer overrun