Ah I didn't know about that. So you can block the child from creating a userns completely... That seems like an unnecessarily big hammer, but also probably 95%

Ah I didn't know about that. So you can block the child from creating a userns completely... That seems like an unnecessarily big hammer, but also probably 95% of cases works fine? I think probably we want an inherited mask of what capabilities you can get in child namespaces. I think I heard someone proposed that upstream but I haven't seen the patches.