[   61.929518] 
[   61.931182] =============================================
[   61.936689] [ INFO: possible recursive locking detected ]
[   61.942196] 4.4.0+ #0 Not tainted
[   61.945620] ---------------------------------------------
[   61.951125] kworker/u4:4/2315 is trying to acquire lock:
[   61.956631]  (&(&nf_conntrack_locks[i])->rlock){+.....}, at: [<ffffffff820fb7cd>] nf_conntrack_lock+0xd/0x50
[   61.967136] 
[   61.967136] but task is already holding lock:
[   61.973077]  (&(&nf_conntrack_locks[i])->rlock){+.....}, at: [<ffffffff820fb7cd>] nf_conntrack_lock+0xd/0x50
[   61.983516] 
[   61.983516] other info that might help us debug this:
[   61.990151]  Possible unsafe locking scenario:
[   61.990151] 
[   61.996178]        CPU0
[   61.998732]        ----
[   62.001287]   lock(&(&nf_conntrack_locks[i])->rlock);
[   62.006687]   lock(&(&nf_conntrack_locks[i])->rlock);
[   62.012087] 
[   62.012087]  *** DEADLOCK ***
[   62.012087] 
[   62.018111]  May be due to missing lock nesting notation
[   62.018111] 
[   62.025008] 4 locks held by kworker/u4:4/2315:
[   62.029559]  #0:  ("%s""netns"){.+.+.+}, at: [<ffffffff8118860e>] process_one_work+0x17e/0x690
[   62.038898]  #1:  (net_cleanup_work){+.+.+.}, at: [<ffffffff8118860e>] process_one_work+0x17e/0x690
[   62.048700]  #2:  (net_mutex){+.+.+.}, at: [<ffffffff8206a63a>] cleanup_net+0x7a/0x270
[   62.057375]  #3:  (&(&nf_conntrack_locks[i])->rlock){+.....}, at: [<ffffffff820fb7cd>] nf_conntrack_lock+0xd/0x50
[   62.068371] 
[   62.068371] stack backtrace:
[   62.072841] CPU: 1 PID: 2315 Comm: kworker/u4:4 Not tainted 4.4.0+ #0
[   62.079390] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   62.088723] Workqueue: netns cleanup_net
[   62.092876]  ffffffff83bf3f90 ffff8800baa9bb20 ffffffff8185e0cc ffffffff83bf3f90
[   62.100905]  ffff8800baa9bbf8 ffffffff811bf55c 00000000000b9f40 ffff8800baa9bbd8
[   62.108919]  0000000000000003 0000000000000000 ffff8800baa9bb60 ffffffff811da3bd
[   62.116912] Call Trace:
[   62.119472]  [<ffffffff8185e0cc>] dump_stack+0x4e/0x82
[   62.124733]  [<ffffffff811bf55c>] __lock_acquire+0x1a5c/0x1ba0
[   62.130676]  [<ffffffff811da3bd>] ? debug_lockdep_rcu_enabled+0x1d/0x20
[   62.137400]  [<ffffffff81272b94>] ? free_one_page+0x34/0x3e0
[   62.143167]  [<ffffffff811c00ed>] lock_acquire+0xed/0x210
[   62.148676]  [<ffffffff820fb7cd>] ? nf_conntrack_lock+0xd/0x50
[   62.154618]  [<ffffffff825a2396>] _raw_spin_lock+0x36/0x50
[   62.160211]  [<ffffffff820fb7cd>] ? nf_conntrack_lock+0xd/0x50
[   62.166163]  [<ffffffff820fb7cd>] nf_conntrack_lock+0xd/0x50
[   62.171933]  [<ffffffff821142dc>] ctnl_untimeout.isra.4+0xdc/0x110
[   62.178250]  [<ffffffff82114338>] cttimeout_net_exit+0x28/0x80
[   62.184191]  [<ffffffff820694f3>] ops_exit_list.isra.4+0x33/0x60
[   62.190304]  [<ffffffff8206a769>] cleanup_net+0x1a9/0x270
[   62.195826]  [<ffffffff811886ab>] process_one_work+0x21b/0x690
[   62.201767]  [<ffffffff8118860e>] ? process_one_work+0x17e/0x690
[   62.207880]  [<ffffffff81188b69>] worker_thread+0x49/0x490
[   62.213473]  [<ffffffff81188b20>] ? process_one_work+0x690/0x690
[   62.219588]  [<ffffffff81188b20>] ? process_one_work+0x690/0x690
[   62.225704]  [<ffffffff8118f84a>] kthread+0xea/0x100
[   62.230788]  [<ffffffff8118f760>] ? kthread_create_on_node+0x1f0/0x1f0
[   62.237423]  [<ffffffff825a356f>] ret_from_fork+0x3f/0x70
[   62.242929]  [<ffffffff8118f760>] ? kthread_create_on_node+0x1f0/0x1f0
Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts.
2019/10/06 07:27:34 parsed 1 programs
2019/10/06 07:27:34 executed programs: 0
[   67.149417] IPv6: ADDRCONF(NETDEV_CHANGE): nr2: link becomes ready
[   67.156475] IPv6: ADDRCONF(NETDEV_CHANGE): nr0: link becomes ready
[   67.166744] IPv6: ADDRCONF(NETDEV_CHANGE): nr1: link becomes ready
[   67.173694] IPv6: ADDRCONF(NETDEV_CHANGE): nr4: link becomes ready
[   67.182458] IPv6: ADDRCONF(NETDEV_CHANGE): nr3: link becomes ready
[   67.190298] IPv6: ADDRCONF(NETDEV_CHANGE): nr5: link becomes ready