rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P136/1:b..l
	(detected by 0, t=10502 jiffies, g=4317, q=185)
task:kworker/u4:1    state:R  running task     stack:    0 pid:  136 ppid:     2 flags:0x00000008
Workqueue: bat_events batadv_nc_worker
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6780
 arm64_preempt_schedule_irq+0x174/0x2c4 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+0x280/0x77c kernel/locking/lockdep.c:5626
 rcu_lock_acquire+0x40/0x4c include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xd0/0x580 net/batman-adv/network-coding.c:723
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: rcu_preempt kthread starved for 10500 jiffies! g4317 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+0x308/0x5e8 arch/arm64/kernel/process.c:518
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xf10/0x1e48 kernel/sched/core.c:6376
 preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6780
 arm64_preempt_schedule_irq+0x174/0x2c4 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]
 timer_delete_sync+0x108/0x210 kernel/time/timer.c:1397
 del_timer_sync include/linux/timer.h:198 [inline]
 schedule_timeout+0x1e0/0x344 kernel/time/timer.c:1915
 rcu_gp_fqs_loop+0x26c/0x13d4 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145
 kthread+0x37c/0x45c 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-executor.0  state:R  running task     stack:    0 pid: 4124 ppid:  3993 flags:0x00000001
Call trace:
 __switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
 lockdep_recursion_inc kernel/locking/lockdep.c:431 [inline]
 lock_acquire+0x1fc/0x77c kernel/locking/lockdep.c:5622
 0xfffff00000000000