** Summary changed: - Removal of CONFIG_NS from 2.6.32-32 breaks applications + Removal of CONFIG_NET_NS from 2.6.32-32 breaks applications
** Description changed: - LP #700295 removed CONFIG_NS from linux-image-2.6.32-32 which was + LP #700295 removed CONFIG_NET_NS from linux-image-2.6.32-32 which was present in linux-image-2.6.32-31 and all previous versions (at least in the -server variant). The reason given is that destroying namespaces takes a large amount of time (this is true, and I believe is an RCU sync issue). If you create and delete a lot of namespaces, it can act as a DoS. However, this breaks functionality for existing applications using LTS kernels and using namespaces in relatively static configurations (i.e. ones where non-root users cannot rapidly create and delete namespaces). This seems to me to be an unreasonable change, as LTS kernel changes are not meant to remove existing functionality. We have a production application (well, one week away from production) which suddenly broke due to this. As we are only using LTS for security updates etc., this is rather unfortunate, as we now cannot take any further kernel patches (unless this is reverted), which is rather the point of LTS. Worse still, later kernels are WORSE in their stability for namespace configurations, so we cannot move to 2.6.38 (see LP #843892). It seems to me a more appropriate fix to LP #700295 would have been to disable the use of network namespaces in vsftp, which would then leave existing users who do allow rapid cycling of namespaces to carry on regardless. This must be a trivial patch in vsftp as it must already cope with failure of the clone() syscall to support CLONE_NEWNS, as that's how it works on existing kernels. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/844185 Title: Removal of CONFIG_NET_NS from 2.6.32-32 breaks applications To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/844185/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
