Messages in this thread | | | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] User chroot | Date | 26 Jun 2001 17:45:15 -0700 |
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Followup to: <E15F3KH-0003fd-00@pmenage-dt.ensim.com> By author: Paul Menage <pmenage@ensim.com> In newsgroup: linux.dev.kernel > > It could potentially be useful for a network daemon (e.g. a simplified > anonymous FTP server) that wanted to be absolutely sure that neither it > nor any of its libraries were being tricked into following a bogus > symlink, or a "/../" in a passed filename. After initialisation, the > daemon could chroot() into its data directory, and safely only serve > the set of files within that directory hierarchy. > > This could be regarded as the wrong way to solve such a problem, but > this kind of bug seems to be occurring often enough on BugTraq that it > might be useful if you don't have the resources to do a full security > audit on your program (or if the source to some of your libraries > isn't available). >
If the source to some of your libraries aren't available, you have no clue when/why/if they will try to access other files in the filesystem. Since libc WILL do this, a random chroot() breaks libc (unless you can set up a proper root environment), and therefore pretty much anything else is pointless.
-hpa
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