Re: Proposed change to setre[ug]id()

H. Peter Anvin (hpa@freya.yggdrasil.com)
19 Jun 1996 01:08:19 GMT

Followup to: <199606190223.EAA26021@hera.cuci.nl>
By author: srb@cuci.nl (Stephen R. van den Berg)
In newsgroup: linux.dev.kernel
>
> "Theodore Y. Ts'o" <tytso@MIT.EDU> wrote:
> >There are two problems; one is the one you pointed out, and the othe=
r is
> >programs which drop the setuid bits, thinking they are then secure, =
and
> >then start doing unsafe things like using gets() and statically-size=
d
> >buffers on the stack.
>=20
> Hmmm..., indeed, and then construct a setuid() system call.
> Well, in that light, the current code looks just fine as it is.

I have only one comment: dlopen().

Just because you're in the same process (no exec) doesn't mean the
code comes from the same file.

If we want to emulate HP/UX's setresuid() facility, then let's
implement a setresuid() call [maybe that should be setresfuid()], but
don't break the current setreuid() implementation -- ESPECIALLY not
since it would make secure programs suddenly insecure!

-hpa

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