syzbot

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.3.529/6301 is trying to acquire lock:
ffff888078600d00 (team->team_lock_key#2){+.+.}-{3:3}, at: team_port_change_check drivers/net/team/team.c:3014 [inline]
ffff888078600d00 (team->team_lock_key#2){+.+.}-{3:3}, at: team_device_event+0x1d2/0x9e0 drivers/net/team/team.c:3040

but task is already holding lock:
ffff888078600d00 (team->team_lock_key#2){+.+.}-{3:3}, at: team_del_slave+0x2e/0x1e0 drivers/net/team/team.c:2004

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

       CPU0
       ----
  lock(team->team_lock_key#2);
  lock(team->team_lock_key#2);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by syz.3.529/6301:
 #0: ffffffff8d238308 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d238308 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647
 #1: ffff888078600d00 (team->team_lock_key#2){+.+.}-{3:3}, at: team_del_slave+0x2e/0x1e0 drivers/net/team/team.c:2004

stack backtrace:
CPU: 1 PID: 6301 Comm: syz.3.529 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 __lock_acquire+0x1227/0x7c60 kernel/locking/lockdep.c:-1
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 team_port_change_check drivers/net/team/team.c:3014 [inline]
 team_device_event+0x1d2/0x9e0 drivers/net/team/team.c:3040
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 dev_close_many+0x28d/0x400 net/core/dev.c:1650
 vlan_device_event+0x1244/0x1fa0 net/8021q/vlan.c:475
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 dev_close_many+0x28d/0x400 net/core/dev.c:1650
 dev_close+0x14c/0x200 net/core/dev.c:1672
 team_port_del+0x4c9/0xc40 drivers/net/team/team.c:1363
 team_del_slave+0x39/0x1e0 drivers/net/team/team.c:2005
 do_set_master net/core/rtnetlink.c:2561 [inline]
 do_setlink+0xe02/0x3980 net/core/rtnetlink.c:2786
 rtnl_setlink+0x35b/0x450 net/core/rtnetlink.c:3061
 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg+0x190/0x250 net/socket.c:2526
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb25cdcaec9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb25b032038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb25d021fa0 RCX: 00007fb25cdcaec9
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000008
RBP: 00007fb25ce4df91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb25d022038 R14: 00007fb25d021fa0 R15: 00007ffdcd00cc98
 </TASK>