============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.1470/10949 is trying to acquire lock:
ffff8881131c4e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: __netdev_update_features+0xd27/0x1ef0

but task is already holding lock:
ffff8881131c4e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: dev_ethtool+0x47e/0x29c0
and the lock comparison function returns 0:

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

       CPU0
       ----
  lock(&dev_instance_lock_key#23);
  lock(&dev_instance_lock_key#23);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by syz.0.1470/10949:
 #0: ffffffff9002d500 (rtnl_mutex){+.+.}-{4:4}, at: dev_ethtool+0x3a0/0x29c0
 #1: ffff8881131c4e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: dev_ethtool+0x47e/0x29c0

stack backtrace:
CPU: 1 UID: 0 PID: 10949 Comm: syz.0.1470 Not tainted syzkaller #0 PREEMPT(full) 
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_deadlock_bug+0x279/0x290
 __lock_acquire+0x24df/0x2cf0
 lock_acquire+0x106/0x350
 __mutex_lock+0x19d/0x1550
 __netdev_update_features+0xd27/0x1ef0
 netdev_update_features+0x6f/0x100
 macvlan_device_event+0x559/0x880
 notifier_call_chain+0x1a5/0x3d0
 netdev_features_change+0x8d/0xd0
 dev_ethtool+0x1f09/0x29c0
 dev_ioctl+0x392/0x1150
 sock_do_ioctl+0x23e/0x320
 sock_ioctl+0x57a/0x7e0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x174/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4aa159de99
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:00007f4a9f7d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4aa1826090 RCX: 00007f4aa159de99
RDX: 0000200000000080 RSI: 0000000000008946 RDI: 000000000000000b
RBP: 00007f4aa1633eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4aa1826128 R14: 00007f4aa1826090 R15: 00007fffbaf144e8
 </TASK>
