Re: Stack Smashing and no-exec

Kragen (kragen@pobox.com)
Fri, 7 Aug 1998 21:16:35 -0400 (EDT)


On Fri, 7 Aug 1998, Jon M. Taylor wrote:
> As long as Linux is a traditional monolithic Unix-like kernel, I
> think this is a reasonable attitude to have. Linus is correct. The suid
> root programs should be fixed. If that task is difficult, use bounds
> checking or whatever you need to be able to fix the problems.

I think some kind of small-interface solution like bounds-checking
compilers should help considerably -- but, of course, it's not a
panacea.

> Debugging
> device drivers can be difficult too sometimes. All you can do is your
> best, but I'd hope you would be willing to put forth a bit more effort to
> ensure that something with root privs is clean.
>
> I think this situation is a very good argument in favor of ACLs.
> Root is too blunt an instrument. It creates "implicit microkerneling",
> where any special priv needs require the needy code to in effect become
> part of the OS.

I'm not clear on how ACLs help. (Do you mean filesystem ACLs?)

The "capability" stuff in 2.1 should help quite a bit with this. Lots
of things are setuid root so they can bind a reserved port, for
example. I'll be a lot happier when I can run named as a normal user!

Kragen

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