On Tue, 7 Sept 2021 at 23:40, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > > On Mon, Sep 06, 2021 at 04:56:44PM +0200, Miklos Szeredi wrote: > > On Mon, 6 Sept 2021 at 16:39, Dr. David Alan Gilbert > > <dgilbert@xxxxxxxxxx> wrote: > > > > > IMHO the real problem here is that the user/trusted/system/security > > > 'namespaces' are arbitrary hacks rather than a proper namespacing > > > mechanism that allows you to create new (nested) namespaces and associate > > > permissions with each one. > > > > Indeed. > > > > This is what Eric Biederman suggested at some point for supporting > > trusted xattrs within a user namespace: > > > > | For trusted xattrs I think it makes sense in principle. The namespace > > | would probably become something like "trusted<ns-root-uid>.". > > > > Theory sounds simple enough. Anyone interested in looking at the details? > > So this namespaced trusted.* xattr domain will basically avoid the need > to have CAP_SYS_ADMIN in init_user_ns, IIUC. I guess this is better > than giving CAP_SYS_ADMIN in init_user_ns. That's the objective, yes. I think the trick is getting filesystems to store yet another xattr type. Thanks, Miklos