rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4455/1:b..l (detected by 0, t=10502 jiffies, g=5909, q=123 ncpus=2) task:kworker/u4:11 state:R running task stack:0 pid:4455 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:5245 [inline] __schedule+0xee4/0x1c98 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 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 starved for 10504 jiffies! g5909 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:16 ppid:2 flags:0x00000008 Call trace: __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553 context_switch kernel/sched/core.c:5245 [inline] __schedule+0xee4/0x1c98 kernel/sched/core.c:6558 schedule+0xc4/0x170 kernel/sched/core.c:6634 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 1: task:syz.0.64 state:R running task stack:0 pid:4603 ppid:4225 flags:0x00000000 Call trace: __switch_to+0x320/0x754 arch/arm64/kernel/process.c:553 0xffffaf3e6c9bc500 0xffffad296468