Re: [gentoo-dev] Hardening a default profile

[Andrew Savchenko <bircoph@gentoo.org>]

[-- Attachment #1: Type: text/plain, Size: 2079 bytes --]

On Thu, 15 Jun 2017 19:52:07 -0500 Matthias Maier wrote:
> > there should be a way of turning these off systematically.  the
> > advantage of the current hardened gcc specs is that one can switch
> > between them using gcc-config.  if these are forced on for the default
> > profile then there will be no easy way to systematically turn them off.
> 
> No - there won't be an easy way for systematically turning off
> SSP and PIE in 17.0 profiles [1,2].
> 
> The hardened toolchain with its different gcc profiles came from a time
> where SSP and PIE were relatively new security features and a certain
> amount of fine-grained control was needed. Further, at that time we were
> talking about external patches against gcc. Nowadays everything is
> upstreamed and (almost) no patches to gcc for hardened profiles are
> applied any more.
> 
> Given the fact that all major linux distributions are following the path
> of improved default hardening features (see for example [1]) and that we
> have been using ssp/pie in hardened profiles for years now the purpose
> of fine-grained control over ssp/pie is also highly questionable.
> 
> The consensus at the moment is that PIE and SSP (as well as stricter
> linker flags) will soon be standard (or, actually *are* already
> standard) compilation options. A per-package override (if absoluetely
> needed) is fine - and, in fact, already in place everywhere where
> needed.

Gentoo is all about choice, remember? :)

It is really good to have them by default, it is bad to force them
on everyone. Security is not always of paramount importance
comparing to other factors, sometimes performance matters more,
e.g. in isolated and restricted non-public HPC environment.

PIE, SSP may lead up to 8% of performance loss[1]. The
stack-protector (especially stack-protector-all or -strong) may
cause even more damage. For compute nodes this may be equivalent to
millions USD loss (depends on the system scale of course).

[1] https://bugs.archlinux.org/task/18864

Best regards,
Andrew Savchenko

[-- Attachment #2: Type: application/pgp-signature, Size: 833 bytes --]