rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P51/1:b..l
	(detected by 1, t=10502 jiffies, g=128129, q=245 ncpus=2)
task:kworker/u4:3    state:R  running task     stack:21264 pid:51    ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90000bc7ac0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 129a939a837d2500
RDX: 0000000000000000 RSI: ffffffff8a8c22a0 RDI: ffffffff8adf1320
RBP: ffffc90000bc7bc8 R08: dffffc0000000000 R09: 1ffffffff215f248
R10: dffffc0000000000 R11: fffffbfff215f249 R12: 0000000000000001
R13: 1ffff92000178f64 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 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+0xeb/0x600 net/batman-adv/network-coding.c:719
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: rcu_preempt kthread starved for 10419 jiffies! g128129 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27376 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 schedule+0xb9/0x180 kernel/sched/core.c:6638
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:36 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_acquire+0x16e/0x4a0 kernel/locking/lockdep.c:5658
Code: 3e 00 0f 85 18 01 00 00 43 c6 44 3d 08 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 <43> c6 44 3d 08 f8 fa 48 c7 c7 00 1e 8c 8a e8 bf bd c9 08 65 ff 05
RSP: 0018:ffffc90000007c40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: c13ea2445530fb00
RDX: 0000000000000000 RSI: ffffffff8adf1300 RDI: ffffffff8adf12c0
RBP: ffffc90000007d48 R08: ffffffff8e1ff3ef R09: 1ffffffff1c3fe7d
R10: dffffc0000000000 R11: fffffbfff1c3fe7e R12: 0000000000000000
R13: 1ffff92000000f94 R14: 0000000000000046 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000300 CR3: 0000000058c5f000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:102
 ktime_get_update_offsets_now+0x44/0x3e0 kernel/time/timekeeping.c:2317
 hrtimer_update_base kernel/time/hrtimer.c:659 [inline]
 hrtimer_interrupt+0x130/0x9c0 kernel/time/hrtimer.c:1855
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:sched_core_balance+0x149/0xde0 kernel/sched/core.c:6237
Code: 8b 8a e8 4a e2 09 00 4c 89 7c 24 38 4c 89 6c 24 28 e9 1a 0c 00 00 48 8b 7c 24 40 e8 c1 f1 dc 08 e8 5c d2 2d 00 fb 41 83 fd 08 <0f> 83 e7 0b 00 00 4e 8d 34 fd 80 39 65 8c 4c 89 f0 48 c1 e8 03 48
RSP: 0018:ffffffff8c807a00 EFLAGS: 00000293
RAX: c13ea2445530fb00 RBX: ffff8880b8e3b848 RCX: c13ea2445530fb00
RDX: dffffc0000000000 RSI: ffffffff8a8c1120 RDI: ffffffff8adf1320
RBP: ffffffff8c807b68 R08: ffff8880b8e3ab03 R09: 1ffff110171c7560
R10: dffffc0000000000 R11: ffffed10171c7561 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff815b0ac0 R15: 0000000000000000
 do_balance_callbacks kernel/sched/core.c:4893 [inline]
 __balance_callbacks kernel/sched/core.c:4947 [inline]
 finish_lock_switch kernel/sched/core.c:5003 [inline]
 finish_task_switch+0x39d/0x8f0 kernel/sched/core.c:5122
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x11d9/0x40e0 kernel/sched/core.c:6562
 schedule_idle+0x4a/0x90 kernel/sched/core.c:6666
 do_idle+0x635/0x680 kernel/sched/idle.c:352
 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:422
 rest_init+0x2dc/0x300 init/main.c:745
 arch_call_rest_init+0xa/0xa init/main.c:905
 start_kernel+0x493/0x53c init/main.c:1152
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>