realpath(3) et al

[Devon H. O'Dell]

Sorry for not including this in the last message to the newsletter; isn't it
also then high time to fix up the signal handling in FreeBSD if this *is*
the case?

Kind regards,

Devon H. O'Dell
Systems and Network Engineer
Simpli, Inc. Web Hosting
http://www.simpli.biz

> -----Oorspronkelijk bericht-----
> Van: owner-freebsd-security at freebsd.org [mailto:owner-freebsd-
> security at freebsd.org] Namens Devon H. O'Dell
> Verzonden: Tuesday, August 12, 2003 1:21 PM
> Aan: 'Peter Jeremy'
> CC: security at freebsd.org
> Onderwerp: RE: realpath(3) et al
> 
> It, would though, be trivial to implement this with a #define based upon
> the
> kernel configuration, would it not? Protecting against stack smashing is
> quite important; I think many hosting environments not using LISP or other
> executable-stack-reliant packages would benefit from this. By negating the
> ability to execute injected code through a buffer overflow, security is
> highly increased. By implementing it as a kernel configuration option, I
> don't think we would lose out at all.
> 
> Kind regards,
> 
> Devon H. O'Dell
> Systems and Network Engineer
> Simpli, Inc. Web Hosting
> http://www.simpli.biz
> 
> > -----Oorspronkelijk bericht-----
> > Van: owner-freebsd-security at freebsd.org [mailto:owner-freebsd-
> > security at freebsd.org] Namens Peter Jeremy
> > Verzonden: Tuesday, August 12, 2003 1:15 PM
> > Aan: Devon H. O'Dell
> > CC: security at freebsd.org
> > Onderwerp: Re: realpath(3) et al
> >
> > On Tue, Aug 12, 2003 at 11:02:16AM +0200, Devon H. O'Dell wrote:
> > >Features such as a protected stack should, IMO, be implemented as soon
> as
> > >possible to keep FreeBSD heads-afloat right now in the security
> sense....
> > >OpenBSD has implemented this already and there are many patches for
> Linux
> > to
> > >do the same... why don't we go ahead and shove some of this code into
> CVS?
> >
> > By "protected" I presume you mean "non-executable".  Whilst making the
> > stack non-executable is trivial, making the system still work isn't.
> > I believe the FreeBSD signal handling still relies on a signal
> > trampoline on the stack.  Some ports also expect an executable stack
> > (most commonly lisp implementations).
> >
> > Some years ago, I tried implementing a non-executable stack on a
> > Solaris box.  Interleaf promptly stopped working so I had to undo the
> > change.
> >
> > Peter
> > _______________________________________________
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> > http://lists.freebsd.org/mailman/listinfo/freebsd-security
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> 
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