============================================
WARNING: possible recursive locking detected
6.9.0-rc5-syzkaller-01434-gac2f438c2a85 #0 Not tainted
--------------------------------------------
rcu_exp_gp_kthr/18 is trying to acquire lock:
ffff888021402aa0 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888021402aa0 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957

but task is already holding lock:
ffff888021402ba0 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888021402ba0 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957

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

       CPU0
       ----
  lock(&htab->buckets[i].lock);
  lock(&htab->buckets[i].lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by rcu_exp_gp_kthr/18:
 #0: ffffffff8e33a248 (rcu_state.exp_wake_mutex){+.+.}-{3:3}, at: rcu_exp_wait_wake kernel/rcu/tree_exp.h:646 [inline]
 #0: ffffffff8e33a248 (rcu_state.exp_wake_mutex){+.+.}-{3:3}, at: rcu_exp_sel_wait_wake+0x1859/0x1df0 kernel/rcu/tree_exp.h:675
 #1: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #1: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #1: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline]
 #1: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444
 #2: ffff888021402ba0 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #2: ffff888021402ba0 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957
 #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline]
 #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444

stack backtrace:
CPU: 1 PID: 18 Comm: rcu_exp_gp_kthr Not tainted 6.9.0-rc5-syzkaller-01434-gac2f438c2a85 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957
 bpf_prog_2c29ac5cdc6b1842+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline]
 __bpf_prog_run include/linux/filter.h:691 [inline]
 bpf_prog_run include/linux/filter.h:698 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline]
 bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2444
 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122
 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122
 __pv_queued_spin_lock_slowpath+0x939/0xc60 kernel/locking/qspinlock.c:560
 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
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 sock_hash_delete_elem+0x17c/0x400 net/core/sock_map.c:957
 bpf_prog_2c29ac5cdc6b1842+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline]
 __bpf_prog_run include/linux/filter.h:691 [inline]
 bpf_prog_run include/linux/filter.h:698 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline]
 bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2444
 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122
 trace_contention_end+0xf5/0x120 include/trace/events/lock.h:122
 __mutex_lock_common kernel/locking/mutex.c:617 [inline]
 __mutex_lock+0x2e5/0xd70 kernel/locking/mutex.c:752
 rcu_exp_wait_wake kernel/rcu/tree_exp.h:646 [inline]
 rcu_exp_sel_wait_wake+0x1859/0x1df0 kernel/rcu/tree_exp.h:675
 kthread_worker_fn+0x500/0xaf0 kernel/kthread.c:841
 kthread+0x2f0/0x390 kernel/kthread.c:388
 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>