============================================
WARNING: possible recursive locking detected
6.6.95-syzkaller #0 Not tainted
--------------------------------------------
ksoftirqd/0/16 is trying to acquire lock:
ffffc900046910d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423

but task is already holding lock:
ffffc900047150d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423

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

4 locks held by ksoftirqd/0/16:
 #0: ffffffff8cd2f880 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2f880 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2188 [inline]
 #0: ffffffff8cd2f880 (rcu_callback){....}-{0:0}, at: rcu_core+0xc51/0x1720 kernel/rcu/tree.c:2467
 #1: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #1: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #1: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
 #1: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf4/0x400 kernel/trace/bpf_trace.c:2362
 #2: ffffc900047150d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423
 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361

stack backtrace:
CPU: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x5d40/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline]
 bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:466
 bpf_prog_fe0ed97373b08409+0x2d/0x4a
 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
 __bpf_prog_run include/linux/filter.h:612 [inline]
 bpf_prog_run include/linux/filter.h:619 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361
 __bpf_trace_contention_end+0xdd/0x130 include/trace/events/lock.h:122
 trace_contention_end+0xe6/0x110 include/trace/events/lock.h:122
 __pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline]
 bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:466
 bpf_prog_fe0ed97373b08409+0x2d/0x4a
 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
 __bpf_prog_run include/linux/filter.h:612 [inline]
 bpf_prog_run include/linux/filter.h:619 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run3+0x1e7/0x400 kernel/trace/bpf_trace.c:2362
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x1e0/0x280 mm/slub.c:3837
 rcu_do_batch kernel/rcu/tree.c:2194 [inline]
 rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 run_ksoftirqd+0x9c/0xf0 kernel/softirq.c:950
 smpboot_thread_fn+0x635/0xa00 kernel/smpboot.c:164
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>