MPTCP: kernel_bind error, err=-98
============================================
WARNING: possible recursive locking detected
5.15.0-rc3-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.5/6247 is trying to acquire lock:
ffff88807bdcbbe0 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x28e/0x8d0 net/mptcp/protocol.c:2738

but task is already holding lock:
ffff88807a668c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline]
ffff88807a668c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x2d/0x8d0 net/mptcp/protocol.c:2720

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

       CPU0
       ----
  lock(k-sk_lock-AF_INET);
  lock(k-sk_lock-AF_INET);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by syz-executor.5/6247:
 #0: ffffffff8d9bad90 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802
 #1: ffffffff8d9bac48 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline]
 #1: ffffffff8d9bac48 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x125/0x1480 net/netlink/genetlink.c:790
 #2: ffff88807a668c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1612 [inline]
 #2: ffff88807a668c60 (k-sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close+0x2d/0x8d0 net/mptcp/protocol.c:2720

stack backtrace:
CPU: 0 PID: 6247 Comm: syz-executor.5 Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2944 [inline]
 check_deadlock kernel/locking/lockdep.c:2987 [inline]
 validate_chain+0x5984/0x8240 kernel/locking/lockdep.c:3776
 __lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5015
 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625
 lock_sock_fast+0x42/0x100 net/core/sock.c:3229
 mptcp_close+0x28e/0x8d0 net/mptcp/protocol.c:2738
 inet_release+0x16e/0x1f0 net/ipv4/af_inet.c:431
 __sock_release net/socket.c:649 [inline]
 sock_release+0x7a/0x140 net/socket.c:677
 mptcp_pm_nl_create_listen_socket net/mptcp/pm_netlink.c:900 [inline]
 mptcp_nl_cmd_add_addr+0x750/0x8c0 net/mptcp/pm_netlink.c:1170
 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
 genl_rcv_msg+0x1032/0x1480 net/netlink/genetlink.c:792
 netlink_rcv_skb+0x200/0x470 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x814/0x9f0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0xa29/0xe50 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 ____sys_sendmsg+0x5b9/0x910 net/socket.c:2409
 ___sys_sendmsg net/socket.c:2463 [inline]
 __sys_sendmsg+0x36f/0x450 net/socket.c:2492
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f00bc196709
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f00b96ec188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f00bc29b020 RCX: 00007f00bc196709
RDX: 0000000000000000 RSI: 0000000020001340 RDI: 0000000000000003
RBP: 00007f00bc1f0cb4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcec62ab8f R14: 00007f00b96ec300 R15: 0000000000022000