Hi Serge, On 11/06, Serge Hallyn wrote: > > Hi Oleg, > > commit 40a0d32d1eaffe6aac7324ca92604b6b3977eb0e : > "fork: unify and tighten up CLONE_NEWUSER/CLONE_NEWPID checks" > breaks lxc-attach in 3.12. That code forks a child which does > setns() and then does a clone(CLONE_PARENT). That way the > grandchild can be in the right namespaces (which the child was > not) and be a child of the original task, which is the monitor.
Thanks... Yes, this is what 40a0d32d1ea explicitly tries to disallow. > Is there a real danger in allowing CLONE_PARENT > when current->nsproxy->pidns_for_children is not our pidns, > or was this done out of an "over-abundance of caution"? I am not sure... This all was based on the long discussion, and it was decided that the CLONE_PARENT check should be consistent wrt CLONE_NEWPID and pidns_for_children != task_active_pid_ns(). > Can we > safely revert that new extra check? Well, usually we do not break user-space, but I am not sure about this case... Eric, Andy, what do you think? And if we allow CLONE_PARENT when ->pidns_for_children was changed, should we also allow, say, CLONE_NEWPID && CLONE_PARENT ? Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
