Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!philabs!seismo!hao!hplabs!sri-unix!bob@ucla-locus From: bob%ucla-locus@sri-unix.UUCP Newsgroups: net.unix-wizards Subject: Re: chroot() Message-ID: <2849@sri-arpa.UUCP> Date: Wed, 6-Jul-83 23:12:04 EDT Article-I.D.: sri-arpa.2849 Posted: Wed Jul 6 23:12:04 1983 Date-Received: Mon, 11-Jul-83 00:27:07 EDT Lines: 18 From: Bob EnglishActually, the chroot call is not the problem. Chroot works the same way as chdir, but on a different incore directory. In order to create a secure sub-tree, you'd have to modify namei so that it checks for the root directory when ever it follows a path "up" the tree. A simpler, but less complete, solution is to make the directory above the proposed root inaccessible to anyone in the "guest" category. This has unfortunate side effects (pwd stops working, users can't exec csh in the directory, etc.), but nothing that can't be overcome. I can't perform an experiment (chroot doesn't work to well here), but I'd like to know what a pwd in /usr/guest yields. --bob--