Kernel bug? unregister_netdevice: waiting for lo to become

I use one of my Linodes for network-based experiments that involve heavy use of network namespaces. Intermittently, when the application tries to tear down one of these namespaces, something in the kernel gets stuck in a loop emitting this message forever (until rebooted):

Dec X XX:XX:XX XXXXX kernel: unregister_netdevice: waiting for lo to become free. Usage count = 1

Once it gets into this state, new network namespaces cannot be created until the machine is rebooted. Also, the message is logged at high severity and syslogd spams every active terminal with it, making any interaction with the system painful.

I have been able to find some public bug reports relating to this message …

* https://bugzilla.redhat.com/show_bug.cgi?id=880394

• https://bugs.launchpad.net/ubuntu/+sour … ug/1065434">https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1065434

• https://bugs.launchpad.net/ubuntu/+sour … ug/1181315">https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1181315

… but they all apply to kernels much older than the Linode stock kernel (I have 3.16.5-x86_64-linode46).

I do not know how to debug further; any advice at all would be appreciated.