rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (2 ticks this GP) idle=c05c/1/0x4000000000000000 softirq=17392/17392 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=11333, q=765 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: bat_events batadv_dat_purge
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3804 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3824 [inline]
RIP: 0010:validate_chain+0xa4/0x2140 kernel/locking/lockdep.c:3879
Code: c6 7b 19 a5 8d e8 5c 8e e5 ff 90 0f 0b 90 90 90 48 bb eb 83 b5 80 46 86 c8 61 49 0f af df 48 c1 eb 2d 48 8b 04 dd 60 63 5d 93 <48> 85 c0 0f 94 c1 48 83 c0 f8 0f 94 c2 08 ca 0f 84 24 01 00 00 e8
RSP: 0018:ffffc90000a08998 EFLAGS: 00000807
RAX: ffffffff93a1b6b8 RBX: 0000000000058f69 RCX: 0000000000040000
RDX: 0000000000000000 RSI: ffff88801daca968 RDI: ffff88801dac9e00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff84c085ab
R10: ffffc90000a08ca0 R11: fffff52000141196 R12: 0000000000000000
R13: ffff88801daca8f0 R14: ffff88801daca968 R15: a26fb770857742d4
FS:  0000000000000000(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555583b20808 CR3: 0000000073832000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline]
 debug_activate kernel/time/hrtimer.c:484 [inline]
 enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088
 __run_hrtimer kernel/time/hrtimer.c:1778 [inline]
 __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline]
RIP: 0010:__local_bh_enable_ip+0x135/0x1c0 kernel/softirq.c:414
Code: 8b e8 0f c2 d9 09 65 66 8b 05 7f 0f 14 11 66 85 c0 75 5a bf 01 00 00 00 e8 68 32 0b 00 e8 d3 46 42 00 fb 65 8b 05 5b 0f 14 11 <85> c0 75 05 e8 92 f5 ad ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc90000ac7980 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 0000000000000201 RCX: a2ec382aacffc100
RDX: 0000000000000006 RSI: ffffffff8d96ea93 RDI: ffffffff8be1b740
RBP: ffffc90000ac7a08 R08: ffffffff8f9fdef7 R09: 1ffffffff1f3fbde
R10: dffffc0000000000 R11: fffffbfff1f3fbdf R12: ffffffff8b29eb8a
R13: ffff88802a885378 R14: dffffc0000000000 R15: 1ffff92000158f30
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:185 [inline]
 batadv_dat_purge+0x2da/0x3c0 net/batman-adv/distributed-arp-table.c:204
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g11333 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=4349
rcu: rcu_preempt kthread starved for 10502 jiffies! g11333 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>