syzbot

============================================
WARNING: possible recursive locking detected
6.1.90-syzkaller #0 Not tainted
--------------------------------------------
syz-executor177/3546 is trying to acquire lock:
ffff888076498a40 (&stab->lock){+...}-{2:2}, at: __sock_map_delete net/core/sock_map.c:419 [inline]
ffff888076498a40 (&stab->lock){+...}-{2:2}, at: sock_map_delete_elem+0x161/0x230 net/core/sock_map.c:451

but task is already holding lock:
ffff88807649fa40 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:495

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-executor177/3546:
 #0: ffff88807eb4b130 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1748 [inline]
 #0: ffff88807eb4b130 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:119 [inline]
 #0: ffff88807eb4b130 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1c8/0x910 net/core/sock_map.c:580
 #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: sock_map_sk_acquire net/core/sock_map.c:120 [inline]
 #1: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: sock_map_update_elem_sys+0x1d4/0x910 net/core/sock_map.c:580
 #2: ffff88807649fa40 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:495
 #3: ffff8880192f6290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
 #3: ffff8880192f6290 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:147 [inline]
 #3: ffff8880192f6290 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xcc/0x5d0 net/core/sock_map.c:182
 #4: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #4: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #4: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
 #4: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2312

stack backtrace:
CPU: 0 PID: 3546 Comm: syz-executor177 Not tainted 6.1.90-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2983 [inline]
 check_deadlock kernel/locking/lockdep.c:3026 [inline]
 validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
 __sock_map_delete net/core/sock_map.c:419 [inline]
 sock_map_delete_elem+0x161/0x230 net/core/sock_map.c:451
 bpf_prog_bd09fd94307bc10c+0x63/0x67
 bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
 bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312
 __bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:94
 trace_kfree include/trace/events/kmem.h:94 [inline]
 kfree+0xf6/0x190 mm/slab_common.c:994
 sk_psock_free_link include/linux/skmsg.h:416 [inline]
 sock_map_del_link net/core/sock_map.c:160 [inline]
 sock_map_unref+0x3ac/0x5d0 net/core/sock_map.c:182
 sock_map_update_common+0x4ec/0x5b0 net/core/sock_map.c:508
 sock_map_update_elem_sys+0x55b/0x910 net/core/sock_map.c:584
 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1448
 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:4993
 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f10605308e9
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:00007ffd9a2272c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ffd9a227498 RCX: 00007f10605308e9
RDX: 0000000000000020 RSI: 0000000020000b40 RDI: 0000000000000002
RBP: 00007f10605a3610 R08: 00007ffd9a227498 R09: 0000