Oleg Nesterov [oleg@xxxxxxxxxx] wrote: | On 08/02, sukadev@xxxxxxxxxx wrote: | > | > Oleg Nesterov [oleg@xxxxxxxxxx] wrote: | > | > | > | > + if (pid_ns != &init_pid_ns) { | > | > | > | > + zap_pid_ns_processes(pid_ns); | > | > | > | > + pid_ns->child_reaper = init_pid_ns.child_reaper; | > | | > | OOPS. I didn't notice this before, but this is not right too (regardless | > | of multi-threaded init problems). | > | | > | We should not "reset" ->child_reaper here, we may have exiting tasks | > | which will re-parent their ->children to global init. | > | | > | No, we are still /sbin/init of this namespace even if we are exiting, | > | ->child_reaper should point to us, at least until zap_pid_ns_processes() | > | completes. | > | > Yes, we are resetting the reaper _after_ zap_pid_ns_processes() completes | > right ? (all other processes in the namespace must have exited). | | OOPS again :) Can't understand how I managed to misread this code. | | This means that we should take care about multi-thread init exit, | otherwise the non-root user can crash the kernel. | | >From reply to Kirill's message: | | > Still. A non-root user does clone(CLONE_PIDNS), then clone(CLONE_THREAD), Agree we should fix the crash. But we need CAP_SYS_ADMIN to clone pid or other namespaces - this is enforced in copy_namespaces() and unshare_nsproxy_namespaces() Suka _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers