============================================
WARNING: possible recursive locking detected
6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Not tainted
--------------------------------------------
kworker/1:4/5897 is trying to acquire lock:
ffffc900052830d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427

but task is already holding lock:
ffffc90004da50d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&rb->spinlock);
  lock(&rb->spinlock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

6 locks held by kworker/1:4/5897:
 #0: ffff88801ac81148 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac81148 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900041a7d00 ((work_completion)(&(&ipvs->defense_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900041a7d00 ((work_completion)(&(&ipvs->defense_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8e93c920 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #2: ffffffff8e93c920 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2561 [inline]
 #2: ffffffff8e93c920 (rcu_callback){....}-{0:0}, at: rcu_core+0xa37/0x17a0 kernel/rcu/tree.c:2823
 #3: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #3: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2350 [inline]
 #3: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run3+0x24c/0x5a0 kernel/trace/bpf_trace.c:2393
 #4: ffffc90004da50d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427
 #5: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #5: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #5: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2350 [inline]
 #5: ffffffff8e93c860 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2392

stack backtrace:
CPU: 1 UID: 0 PID: 5897 Comm: kworker/1:4 Not tainted 6.12.0-syzkaller-05480-gfcc79e1714e8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: events_long defense_work_handler
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
 check_deadlock kernel/locking/lockdep.c:3089 [inline]
 validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:478 [inline]
 bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:470
 bpf_prog_fe0ed97373b08409+0x2e/0x4b
 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline]
 bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2392
 trace_contention_begin+0x117/0x140 include/trace/events/lock.h:95
 __pv_queued_spin_lock_slowpath+0x114/0xdb0 kernel/locking/qspinlock.c:402
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline]
 queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x272/0x370 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:478 [inline]
 bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:470
 bpf_prog_fe0ed97373b08409+0x2e/0x4b
 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline]
 bpf_trace_run3+0x33a/0x5a0 kernel/trace/bpf_trace.c:2393
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x355/0x420 mm/slub.c:4680
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 update_defense_level+0x8ec/0xcf0 net/netfilter/ipvs/ip_vs_ctl.c:210
 defense_work_handler+0x22/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:235
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>