home *** CD-ROM | disk | FTP | other *** search
- From: itschere@techfak.uni-bielefeld.de
- Subject: Re: XATTR structure for biosfs entries
- Date: Wed, 10 Nov 93 15:59:38 MET
- In-Reply-To: <9311101240.AA16548@math.uni-muenster.de>; from "Ulrich Kuehn" at Nov 10, 93 01:40:20 pm
-
- Hi Ulrich,
-
- > |> Ah, yes, this one doesn't sound bad :-) but just at this moment a more
- > |> general problems comes to my mind: If the device driver has full access
- > |> to its XATTR field, it can also change its own uid/gid or so. This won't
- > |> matter for the built-in ones, but someone _could_ write a driver which
- > |> can self-change its uid to superuser... Looks a bit like a security hole :-(
- > |>
- >
- > Well, if you can put your own device driver into the system folder, then
- > THAT is a security hole, as a device driver can (in priciple) do anything
- > it wants, even change the uid of the current process, and it does not need
- > access to its own file uid/gid field. I think this is definitly not a
- > security hole.
-
- Well you mustn't put an XDD driver into the system folder, you can also
- start it up using "normal" dcntl's and come to the same problem... :-(
-
- The longer I think about this, the more my head begins to hurt...
-
- So, to make it really secure, it looks like Dcntl's on the biosfs should
- be limited to superuser processes.
-
- bye,
- TeSche
- --
- PS: If the above written looks weird, than that's because it probably IS.
- WhoDunnIt: Torsten Scherer (Schiller, TeSche...)
- Technical Faculty, University of Bielefeld, Germany (52'5"N 8'35"E)
- EMail: itschere@techfak.uni-bielefeld.de / tesche@dave.hrz.uni-bielefeld.de
-