syzbot

IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
device team1 entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): macvtap1: link is not ready
8021q: adding VLAN 0 to HW filter on device macvtap1
============================================
WARNING: possible recursive locking detected
4.19.142-syzkaller #0 Not tainted
--------------------------------------------
syz-executor185/6487 is trying to acquire lock:
000000001de11139 (&team->lock){+.+.}, at: team_vlan_rx_add_vid+0x38/0x1e0 drivers/net/team/team.c:1896

but task is already holding lock:
00000000c5ea76c1 (&team->lock){+.+.}, at: team_add_slave+0x98/0x1eb0 drivers/net/team/team.c:1975

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

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

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by syz-executor185/6487:
 #0: 0000000040c831f1 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
 #0: 0000000040c831f1 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4775
 #1: 00000000c5ea76c1 (&team->lock){+.+.}, at: team_add_slave+0x98/0x1eb0 drivers/net/team/team.c:1975

stack backtrace:
CPU: 0 PID: 6487 Comm: syz-executor185 Not tainted 4.19.142-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 print_deadlock_bug kernel/locking/lockdep.c:1763 [inline]
 check_deadlock kernel/locking/lockdep.c:1807 [inline]
 validate_chain kernel/locking/lockdep.c:2403 [inline]
 __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3415
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907
 __mutex_lock_common kernel/locking/mutex.c:925 [inline]
 __mutex_lock+0xd7/0x1260 kernel/locking/mutex.c:1072
 team_vlan_rx_add_vid+0x38/0x1e0 drivers/net/team/team.c:1896
 vlan_add_rx_filter_info+0x13c/0x1c0 net/8021q/vlan_core.c:210
 __vlan_vid_add net/8021q/vlan_core.c:278 [inline]
 vlan_vid_add+0x3ee/0x7e0 net/8021q/vlan_core.c:308
 vlan_add_rx_filter_info+0x13c/0x1c0 net/8021q/vlan_core.c:210
 __vlan_vid_add net/8021q/vlan_core.c:278 [inline]
 vlan_vid_add+0x3ee/0x7e0 net/8021q/vlan_core.c:308
 vlan_device_event.cold+0x28/0x2d net/8021q/vlan.c:381
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93
 call_netdevice_notifiers net/core/dev.c:1762 [inline]
 dev_open net/core/dev.c:1442 [inline]
 dev_open+0x128/0x140 net/core/dev.c:1430
 team_port_add drivers/net/team/team.c:1220 [inline]
 team_add_slave+0xa3c/0x1eb0 drivers/net/team/team.c:1976
 do_set_master+0x1c8/0x220 net/core/rtnetlink.c:2321
 rtnl_newlink+0x1270/0x15b0 net/core/rtnetlink.c:3170
 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4778
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:632
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115
 __sys_sendmsg net/socket.c:2153 [inline]
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443759
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 0f fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffef647faa8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000443759
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000306d616574 R08: 0000000001bbbbbb R09: 0000000001bbbbbb
R10: 0000000001bbbbbb R11: 0000000000000246 R12: 00007ffef647fac0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
team0: Device macvtap1 failed to register rx_handler