team0: Device dummy0 failed to register rx_handler
netlink: 'syz.9.2626': attribute type 10 has an invalid length.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.9.2626/16832 is trying to acquire lock:
ffff88816c6eee70 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: ipvlan_uninit+0x147/0x290

but task is already holding lock:
ffff8881beafa8c0 (&port->pnodes_lock){+.+.}-{4:4}, at: ipvlan_device_event+0x489/0xfb0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&port->pnodes_lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       ipvlan_device_event+0x489/0xfb0
       notifier_call_chain+0x1a5/0x3d0
       __dev_open+0x20f/0x850
       __dev_change_flags+0x329/0x820
       netif_change_flags+0x7c/0x1b0
       do_setlink+0xdd6/0x4670
       rtnl_newlink+0x146f/0x1c30
       rtnetlink_rcv_msg+0x802/0xc00
       netlink_rcv_skb+0x226/0x4a0
       netlink_unicast+0x7bd/0x940
       netlink_sendmsg+0x813/0xb40
       sock_sendmsg_nosec+0x13a/0x180
       ____sys_sendmsg+0x54e/0x850
       ___sys_sendmsg+0x2a5/0x360
       __x64_sys_sendmsg+0x1b1/0x290
       do_syscall_64+0x166/0x520
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&dev_instance_lock_key#3){+.+.}-{4:4}:
       __lock_acquire+0x15ff/0x2e50
       lock_acquire+0x115/0x350
       __mutex_lock+0x19d/0x1550
       ipvlan_uninit+0x147/0x290
       unregister_netdevice_many_notify+0x1acd/0x2140
       ipvlan_device_event+0xf1f/0xfb0
       notifier_call_chain+0x1a5/0x3d0
       unregister_netdevice_many_notify+0x17f9/0x2140
       rtnl_dellink+0x5be/0x810
       rtnetlink_rcv_msg+0x802/0xc00
       netlink_rcv_skb+0x226/0x4a0
       netlink_unicast+0x7bd/0x940
       netlink_sendmsg+0x813/0xb40
       sock_sendmsg_nosec+0x13a/0x180
       ____sys_sendmsg+0x54e/0x850
       ___sys_sendmsg+0x2a5/0x360
       __x64_sys_sendmsg+0x1b1/0x290
       do_syscall_64+0x166/0x520
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&port->pnodes_lock);
                               lock(&dev_instance_lock_key#3);
                               lock(&port->pnodes_lock);
  lock(&dev_instance_lock_key#3);

 *** DEADLOCK ***

locks held by syz.9.2626/16832: 2, last CPU#1:
 #0: ffffffff91252640 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x41b/0x810
 #1: ffff8881beafa8c0 (&port->pnodes_lock){+.+.}-{4:4}, at: ipvlan_device_event+0x489/0xfb0

stack backtrace:
CPU: 1 UID: 0 PID: 16832 Comm: syz.9.2626 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_circular_bug+0x2e2/0x300
 check_noncircular+0x12f/0x150
 __lock_acquire+0x15ff/0x2e50
 lock_acquire+0x115/0x350
 __mutex_lock+0x19d/0x1550
 ipvlan_uninit+0x147/0x290
 unregister_netdevice_many_notify+0x1acd/0x2140
 ipvlan_device_event+0xf1f/0xfb0
 notifier_call_chain+0x1a5/0x3d0
 unregister_netdevice_many_notify+0x17f9/0x2140
 rtnl_dellink+0x5be/0x810
 rtnetlink_rcv_msg+0x802/0xc00
 netlink_rcv_skb+0x226/0x4a0
 netlink_unicast+0x7bd/0x940
 netlink_sendmsg+0x813/0xb40
 sock_sendmsg_nosec+0x13a/0x180
 ____sys_sendmsg+0x54e/0x850
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1b1/0x290
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f518799e1d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f51887ff028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5187c25fa0 RCX: 00007f518799e1d9
RDX: 0000000000008084 RSI: 0000200000000600 RDI: 0000000000000003
RBP: 00007f5187a35888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5187c26038 R14: 00007f5187c25fa0 R15: 00007ffc7a54ccc8
 </TASK>
