> Here is the output of the kernel when the "unregister_netdevice" bug was hit
Thanks! And just to verify, that's the full output of all those lines before the next "waiting..." line, right? If so, it looks like the problem in your case is not a kernel socket holding the netns open, it looks like a good-old dst leak, or something else holding a dst, so I'll need to add debug tracking those now... Also, when you reproduce the problem, if you leave it for a while (like, 5 minutes or so), does it resolve itself? Or stay hung and printing the "waiting..." messages forever? Make sure to check the netns addr in the "waiting..." message to verify it's stuck waiting for the *same* netns to close forever, not just reproducing the problem over and over with different netns. I'll get another kernel ready with additional dst debug. I think there is at least one dst leak patch upstream too, I'll check for those. -- 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: In Progress 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