rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11/1:b..l (detected by 1, t=10502 jiffies, g=16565, q=842 ncpus=2) task:kworker/u4:1 state:R running task stack:0 pid:11 ppid:2 flags:0x00000008 Workqueue: bat_events batadv_nc_worker Call trace: __switch_to+0x2f4/0x568 arch/arm64/kernel/process.c:555 context_switch kernel/sched/core.c:5244 [inline] __schedule+0xddc/0x1b18 kernel/sched/core.c:6561 preempt_schedule_irq+0x8c/0x1b8 kernel/sched/core.c:6873 arm64_preempt_schedule_irq+0x44/0x58 arch/arm64/kernel/entry-common.c:265 __el1_irq arch/arm64/kernel/entry-common.c:474 [inline] el1_interrupt+0x3c/0x54 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+0x24c/0x644 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+0xc0/0x554 net/batman-adv/network-coding.c:719 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 rcu: rcu_preempt kthread starved for 10502 jiffies! g16565 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+0x2f4/0x568 arch/arm64/kernel/process.c:555 context_switch kernel/sched/core.c:5244 [inline] __schedule+0xddc/0x1b18 kernel/sched/core.c:6561 schedule+0xc4/0x170 kernel/sched/core.c:6637 schedule_timeout+0x180/0x2cc kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x2a8/0x134c kernel/rcu/tree.c:1706 rcu_gp_kthread+0xc0/0x2f8 kernel/rcu/tree.c:1905 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 17367 Comm: syz.2.6364 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] pc : _raw_spin_unlock_irq+0x44/0x90 kernel/locking/spinlock.c:202 lr : __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] lr : _raw_spin_unlock_irq+0x3c/0x90 kernel/locking/spinlock.c:202 sp : ffff800021577ac0 x29: ffff800021577ac0 x28: ffff0000dbf8bc98 x27: ffff0000f2ecae40 x26: ffff0000dbf8c070 x25: ffff800021577d50 x24: dfff800000000000 x23: ffff0000f2ecb2d8 x22: 1fffe0001e5d965b x21: ffff0000dbf8b780 x20: 0000000000000021 x19: ffff0000f2ecae40 x18: 0000000000000000 x17: 0000000000000000 x16: ffff8000082d3a08 x15: 0000000000000000 x14: 0000000000000001 x13: 0000000000000000 x12: 0000000000ff0100 x11: ff0080000a895d54 x10: 0000000000000003 x9 : 0000000000000000 x8 : 00000000000000e0 x7 : 0000000018000004 x6 : 0000ffffb6582050 x5 : ffff800021577d70 x4 : ffff0000f2ecb2f8 x3 : 0000000000000000 x2 : ffff800021577a00 x1 : ffff800011a5d840 x0 : ffff80018a7b9000 Call trace: arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline] _raw_spin_unlock_irq+0x44/0x90 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x10bc/0x1310 kernel/signal.c:2874 do_signal arch/arm64/kernel/signal.c:1081 [inline] do_notify_resume+0x29c/0x2b28 arch/arm64/kernel/signal.c:1134 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x138 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585