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
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Jun 30 2001 - 21:00:15 EST