Hi Dan, so here are the information for the latest kernel (4.13.0-38.43+hf1711407v20180413b1):
The bug got reproduced: [ 1085.626663] unregister_netdevice: possible namespace leak (netns ffff8d2dc3d34800), have been waiting for 60 seconds [ 1085.626696] (netns ffff8d2dc3d34800): dst ffff8d2dd006db00 expires 0 error 0 obsolete 2 flags 0 refcnt 1 ops ipv4_dst_ops+0x0/0xc0 creator ip_route_output_key_hash_rcu+0x355/0x9c0 If I grep the netns: ffff8d2dc3d34800, it is visible that during first 10 minutes, it outputs more info, then until ~ 1 hour, it says the same message more frequently and then only outputs it ever hour. [ 901.854919] net_namespace: alloced net ffff8d2dc3d34800 [ 1085.626663] unregister_netdevice: possible namespace leak (netns ffff8d2dc3d34800), have been waiting for 60 seconds [ 1085.626696] (netns ffff8d2dc3d34800): dst ffff8d2dd006db00 expires 0 error 0 obsolete 2 flags 0 refcnt 1 ops ipv4_dst_ops+0x0/0xc0 creator ip_route_output_key_hash_rcu+0x355/0x9c0 [ 1095.706659] unregister_netdevice: possible namespace leak (netns ffff8d2dc3d34800), have been waiting for 70 seconds [ 1095.706692] (netns ffff8d2dc3d34800): dst ffff8d2dd006db00 expires 0 error 0 obsolete 2 flags 0 refcnt 1 ops ipv4_dst_ops+0x0/0xc0 creator ip_route_output_key_hash_rcu+0x355/0x9c0 [ 1105.786651] unregister_netdevice: possible namespace leak (netns ffff8d2dc3d34800), have been waiting for 80 seconds [ 1105.786669] (netns ffff8d2dc3d34800): dst ffff8d2dd006db00 expires 0 error 0 obsolete 2 flags 0 refcnt 1 ops ipv4_dst_ops+0x0/0xc0 creator ip_route_output_key_hash_rcu+0x355/0x9c0 [ 1115.866654] unregister_netdevice: possible namespace leak (netns ffff8d2dc3d34800), have been waiting for 90 seconds .... [ 1631.003906] unregister_netdevice: likely namespace leak (netns ffff8d2dc3d34800), have been waiting for 605 seconds [ 1641.147950] unregister_netdevice: likely namespace leak (netns ffff8d2dc3d34800), have been waiting for 616 seconds [ 1651.291981] unregister_netdevice: likely namespace leak (netns ffff8d2dc3d34800), have been waiting for 626 seconds [ 1661.372025] unregister_netdevice: likely namespace leak (netns ffff8d2dc3d34800), have been waiting for 636 seconds [ 1671.452071] unregister_netdevice: likely namespace leak (netns ffff8d2dc3d34800), have been waiting for 646 seconds [ 1681.564110] unregister_netdevice: likely namespace leak (netns ffff8d2dc3d34800), have been waiting for 656 seconds ... [ 4628.301622] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 3603 seconds [ 8252.383668] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 7227 seconds [11877.333159] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 10852 seconds [15502.281254] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 14477 seconds [19127.230600] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 18102 seconds [22752.179625] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 21727 seconds [26377.129256] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 25352 seconds [30002.078342] unregister_netdevice: namespace leak (netns ffff8d2dc3d34800), have been waiting for 28977 seconds The machine continue to run and the docker is still able to create new instances, i.e. there is no complete lock out. The machine continued to run further, and after an ~hour , 3 namespaces leaked. The machine now has load "3", which seems to be an artifact of this. Other than that, it seems to continue to run! -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1711407 Title: unregister_netdevice: waiting for lo to become free Status in linux package in Ubuntu: In Progress Status in linux source package in Trusty: In Progress Status in linux source package in Xenial: In Progress Status in linux source package in Zesty: Won't Fix Status in linux source package in Artful: In Progress Status in linux source package in Bionic: In Progress Bug description: This is a "continuation" of bug 1403152, as that bug has been marked "fix released" and recent reports of failure may (or may not) be a new bug. Any further reports of the problem should please be reported here instead of that bug. -- [Impact] When shutting down and starting containers the container network namespace may experience a dst reference counting leak which results in this message repeated in the logs: unregister_netdevice: waiting for lo to become free. Usage count = 1 This can cause issues when trying to create net network namespace and thus block a user from creating new containers. [Test Case] See comment 16, reproducer provided at https://github.com/fho/docker- samba-loop To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1711407/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
