syzbot

============================================
WARNING: possible recursive locking detected
6.9.0-rc5-syzkaller-00202-g78cfe547607a #0 Not tainted
--------------------------------------------
syz-executor177/5079 is trying to acquire lock:
ffff88802f63f200 (&stab->lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88802f63f200 (&stab->lock){+...}-{2:2}, at: __sock_map_delete net/core/sock_map.c:417 [inline]
ffff88802f63f200 (&stab->lock){+...}-{2:2}, at: sock_map_delete_elem+0x175/0x250 net/core/sock_map.c:449

but task is already holding lock:
ffff88802f63ea00 (&stab->lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88802f63ea00 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:493

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

       CPU0
       ----
  lock(&stab->lock);
  lock(&stab->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

5 locks held by syz-executor177/5079:
 #0: ffff8880202afa58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1673 [inline]
 #0: ffff8880202afa58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:117 [inline]
 #0: ffff8880202afa58 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1cc/0x910 net/core/sock_map.c:578
 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: sock_map_sk_acquire net/core/sock_map.c:118 [inline]
 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: sock_map_update_elem_sys+0x1d8/0x910 net/core/sock_map.c:578
 #2: ffff88802f63ea00 (&stab->lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #2: ffff88802f63ea00 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:493
 #3: ffff88802aa3e290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #3: ffff88802aa3e290 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:145 [inline]
 #3: ffff88802aa3e290 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xcc/0x5e0 net/core/sock_map.c:180
 #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
 #4: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420

stack backtrace:
CPU: 0 PID: 5079 Comm: syz-executor177 Not tainted 6.9.0-rc5-syzkaller-00202-g78cfe547607a #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_map_delete net/core/sock_map.c:417 [inline]
 sock_map_delete_elem+0x175/0x250 net/core/sock_map.c:449
 bpf_prog_029d1888f6cd2729+0x47/0x4b
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:657 [inline]
 bpf_prog_run include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420
 trace_kfree include/trace/events/kmem.h:94 [inline]
 kfree+0x2af/0x3a0 mm/slub.c:4377
 sk_psock_free_link include/linux/skmsg.h:421 [inline]
 sock_map_del_link net/core/sock_map.c:158 [inline]
 sock_map_unref+0x3ac/0x5e0 net/core/sock_map.c:180
 sock_map_update_common+0x4f0/0x5b0 net/core/sock_map.c:506
 sock_map_update_elem_sys+0x55f/0x910 net/core/sock_map.c:582
 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641
 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5648
 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5765 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5765
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8fd95759e9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd7e5f3158 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ffd7e5f3328 RCX: 00007f8fd95759e9
RDX: 0000000000000020 RSI: 000000002000