============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.17/4468 is trying to acquire lock:
ffffc900034390d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1d5/0x5c0 kernel/bpf/ringbuf.c:415

but task is already holding lock:
ffffc9000344d0d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1d5/0x5c0 kernel/bpf/ringbuf.c:415

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

3 locks held by syz.0.17/4468:
 #0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: bpf_test_timer_enter+0x1a/0x140 net/bpf/test_run.c:36
 #1: ffffc9000344d0d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1d5/0x5c0 kernel/bpf/ringbuf.c:415
 #2: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #2: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #2: ffffffff8db2daa0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xbf/0x6b0 kernel/trace/bpf_trace.c:134

stack backtrace:
CPU: 1 PID: 4468 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3090 [inline]
 validate_chain kernel/locking/lockdep.c:3884 [inline]
 __lock_acquire+0x690e/0x7ea0 kernel/locking/lockdep.c:5171
 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1d5/0x5c0 kernel/bpf/ringbuf.c:415
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:466 [inline]
 bpf_ringbuf_reserve+0x58/0x70 kernel/bpf/ringbuf.c:458
 bpf_prog_054a37e0d8938faa+0x2d/0x4a
 bpf_dispatcher_nop_func include/linux/bpf.h:1016 [inline]
 __bpf_prog_run include/linux/filter.h:608 [inline]
 bpf_prog_run include/linux/filter.h:615 [inline]
 bpf_prog_run_array include/linux/bpf.h:1698 [inline]
 trace_call_bpf+0x322/0x6b0 kernel/trace/bpf_trace.c:135
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10018
 perf_trace_lock+0x301/0x390 include/trace/events/lock.h:50
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x8ad/0x920 kernel/locking/lockdep.c:5801
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x6d/0x120 kernel/locking/spinlock.c:194
 __bpf_ringbuf_reserve+0x478/0x5c0 kernel/bpf/ringbuf.c:453
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:466 [inline]
 bpf_ringbuf_reserve+0x58/0x70 kernel/bpf/ringbuf.c:458
 bpf_prog_5f3e9484f0a4724b+0x36/0xa5
 bpf_dispatcher_nop_func include/linux/bpf.h:1016 [inline]
 __bpf_prog_run include/linux/filter.h:608 [inline]
 bpf_prog_run include/linux/filter.h:615 [inline]
 bpf_test_run+0x2b6/0x830 net/bpf/test_run.c:402
 bpf_prog_test_run_skb+0xdaf/0x18e0 net/bpf/test_run.c:1222
 bpf_prog_test_run+0x31c/0x390 kernel/bpf/syscall.c:3748
 __sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5112
 __do_sys_bpf kernel/bpf/syscall.c:5198 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5196 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5196
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb84979fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe707af8c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fb849a25fa0 RCX: 00007fb84979fb19
RDX: 0000000000000050 RSI: 0000200000001dc0 RDI: 000000000000000a
RBP: 00007fb849837b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb849a25fac R14: 00007fb849a25fa0 R15: 00007fb849a25fa0
 </TASK>