======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.3620/25326 is trying to acquire lock:
ffffffff8f68f9b8 (nr_node_list_lock){+...}-{3:3}, at: nr_rt_device_down+0xa9/0x720

but task is already holding lock:
ffffffff8f68f958 (nr_neigh_list_lock){+...}-{3:3}, at: nr_rt_device_down+0x28/0x720

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (nr_neigh_list_lock){+...}-{3:3}:
       lock_acquire+0x120/0x360
       _raw_spin_lock_bh+0x36/0x50
       nr_rt_ioctl+0x390/0xd50
       sock_do_ioctl+0xdc/0x300
       sock_ioctl+0x576/0x790
       __se_sys_ioctl+0xfc/0x170
       do_syscall_64+0xfa/0x3b0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&nr_node->node_lock){+...}-{3:3}:
       lock_acquire+0x120/0x360
       _raw_spin_lock_bh+0x36/0x50
       nr_rt_ioctl+0x193/0xd50
       sock_do_ioctl+0xdc/0x300
       sock_ioctl+0x576/0x790
       __se_sys_ioctl+0xfc/0x170
       do_syscall_64+0xfa/0x3b0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (nr_node_list_lock){+...}-{3:3}:
       validate_chain+0xb9b/0x2140
       __lock_acquire+0xab9/0xd20
       lock_acquire+0x120/0x360
       _raw_spin_lock_bh+0x36/0x50
       nr_rt_device_down+0xa9/0x720
       nr_device_event+0x137/0x150
       notifier_call_chain+0x1b6/0x3e0
       netif_close_many+0x29c/0x410
       netif_close+0x158/0x210
       dev_close+0x10a/0x220
       bpq_device_event+0x377/0x6a0
       notifier_call_chain+0x1b6/0x3e0
       netif_close_many+0x29c/0x410
       netif_close+0x158/0x210
       dev_close+0x10a/0x220
       bond_setup_by_slave+0x5f/0x3f0
       bond_enslave+0x6ca/0x3870
       bond_do_ioctl+0x635/0x9b0
       bond_siocdevprivate+0x17e/0x350
       dev_ifsioc+0xb57/0xf00
       dev_ioctl+0x84c/0x1150
       sock_ioctl+0x719/0x790
       __se_sys_ioctl+0xfc/0x170
       do_syscall_64+0xfa/0x3b0
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  nr_node_list_lock --> &nr_node->node_lock --> nr_neigh_list_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(nr_neigh_list_lock);
                               lock(&nr_node->node_lock);
                               lock(nr_neigh_list_lock);
  lock(nr_node_list_lock);

 *** DEADLOCK ***

2 locks held by syz.0.3620/25326:
 #0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150
 #1: ffffffff8f68f958 (nr_neigh_list_lock){+...}-{3:3}, at: nr_rt_device_down+0x28/0x720

stack backtrace:
CPU: 0 UID: 0 PID: 25326 Comm: syz.0.3620 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+0x189/0x250
 print_circular_bug+0x2ee/0x310
 check_noncircular+0x134/0x160
 validate_chain+0xb9b/0x2140
 __lock_acquire+0xab9/0xd20
 lock_acquire+0x120/0x360
 _raw_spin_lock_bh+0x36/0x50
 nr_rt_device_down+0xa9/0x720
 nr_device_event+0x137/0x150
 notifier_call_chain+0x1b6/0x3e0
 netif_close_many+0x29c/0x410
 netif_close+0x158/0x210
 dev_close+0x10a/0x220
 bpq_device_event+0x377/0x6a0
 notifier_call_chain+0x1b6/0x3e0
 netif_close_many+0x29c/0x410
 netif_close+0x158/0x210
 dev_close+0x10a/0x220
 bond_setup_by_slave+0x5f/0x3f0
 bond_enslave+0x6ca/0x3870
 bond_do_ioctl+0x635/0x9b0
 bond_siocdevprivate+0x17e/0x350
 dev_ifsioc+0xb57/0xf00
 dev_ioctl+0x84c/0x1150
 sock_ioctl+0x719/0x790
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe36f98ec29
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:00007fe3708c0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe36fbd6090 RCX: 00007fe36f98ec29
RDX: 0000200000000180 RSI: 00000000000089f0 RDI: 0000000000000007
RBP: 00007fe36fa11e41 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe36fbd6128 R14: 00007fe36fbd6090 R15: 00007ffd4ac071d8
 </TASK>
8021q: adding VLAN 0 to HW filter on device bond0
bond0: (slave rose0): Enslaving as an active interface with an up link
