Re: [PATCH] powerpc: enable heap randomization for linkstations

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

On Mon, 13 Oct 2008, Scott Wood wrote:

> On Mon, Oct 13, 2008 at 08:05:09PM +0200, Guennadi Liakhovetski wrote:
> > On Mon, 13 Oct 2008, Rog=E9rio Brito wrote:
> >=20
> > > The current defconfig for Linkstation/Kuroboxes has the "Disable Heap
> > > Randomization" option enabled.
> > >=20
> > > Since some of these machines are facing the internet, it helps to hav=
e
> > > heap randomization enabled. This patch enables it.
> >=20
> > Same as the previous patch - this is one of options, that users select=
=20
> > according to their needs. If any specific distribution enables this opt=
ion=20
> > by default in their kernels, they can do this too, don't think this is=
=20
> > critical enough to patch the defconfig.
>=20
> Just because users/distros can change it doesn't mean it's pointless to
> discuss what default is sane, and make changes if the current default
> isn't.
>=20
> For security-related options it's usually best to default to the more
> secure state, especially since the option description talks about it
> being needed mainly for libc5 compatibility -- did libc5 ever even exist
> for powerpc? =20

In a 2.6.27-rc5-ish snapshot I counted 68 enabled and 11 disabled=20
CONFIG_COMPAT_BRK under arch/powerpc/configs/. Ok, enabling it for all=20
would be a bit rude, and one has to start somewhere...

> The only reason it was turned on in the first place was likely the
> "default y", which in turn is there to avoid breaking old x86 distros.

Then maybe it would be better to make default y only for some platforms?

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer