Re: [gentoo-user] Dirty COW, 4.4.8-hardened-r1 how to fix?

[Miroslav Rovis]

Sorry about noticing your reply only now.

Namely, thinking that people over at hardened ML would tell more about
it, I indirectly initiated a thread over at hardened ML:
https://archives.gentoo.org/gentoo-hardened/message/09bbf3bfe59a938f11ac044e891db77e

Will surely check it! And am CC'ing hardened about this patch at the
hardened ML. Maybe they patch and forward the 4.4.8-r1 to 4.4.8-r2 .
---
Only now looked at the patch.

No, you don't get it. And I'm not CC'ing this to hardened ML.

You can't just run the patch for a vanilla kernel onto a
grsecurity-patched kernel. Look up the hardened-sources, and how they
are patched, and what the mm.h and the gup.c in question (there are a
few of so named files in various directories) look in the
hardened-sources, and how they look in the vanilla-sources...

If I'm not mistaken, and I did check it. No, I'm not mistaken, you just
sent me the Linus's patch.

No, wrong. But thanks for trying to help!

On 161025-13:16-0400, Fernando Rodriguez wrote:
> On Tue, Oct 25, 2016 at 07:11:54AM +0200, Miroslav Rovis wrote:
> > On 161021-11:04-0400, Rich Freeman wrote:
> > > On Fri, Oct 21, 2016 at 10:49 AM, Mick <michaelkintzios@×××××.com> wrote:
> > > > https://github.com/dirtycow/dirtycow.github.io/wiki/VulnerabilityDetails
> > >
> > > Not yet:
> > > https://bugs.gentoo.org/show_bug.cgi?id=597624
> > >
> >
> > We are talking grsecurity-patched (kind of stable[*]) kernel sources,
> > the =sys-kernel/hardened-sources-4.4.8-r1 package [**].
> >
> > I read most of the discussion, and I could easily patch the gup.c and
> > mm.h in question, but those files need to be patched before application
> > of the grsecurity patch, and that is a little more complex work.
>
> Did you tried it?
> The patch attached comes straight from the git repo, just run:
>
> # cd /usr/src/linux
> # patch -p1 < path/to/patch
>
> It'll likely work.
>
> >
> > Has anybody done this, as I have limited time available to practice user
> > patching (which in its simplest form, I was able to do here:
> > >=dev-libs/nss-3.24 - Add USE flag to enable SSL key
> > https://bugs.gentoo.org/show_bug.cgi?id=587116#c2 ), in case it can be
> > done with user patching, of course.
> >
> > Anyone?
> >
> > Regards!
> > ---
> > [*] kind of stable, because there are, since about 1 yrs ago, only
> > testing kernel available for the non-paying users ;-(
> >
> > [**] I have to use 4.4.8.r1 because recent kernel all crash with libirt
> > and qemu which I am trying to use:
> > https://bugs.gentoo.org/show_bug.cgi?id=597554
> > --
> > Miroslav Rovis
> > Zagreb, Croatia
> > http://www.CroatiaFidelis.hr
>
>
>
> --
> Fernando Rodriguez

> commit 1294d355881cc5c3421d24fee512f16974addb6c
> Author: Linus Torvalds <torvalds@××××××××××××××××.org>
> Date:   Thu Oct 13 13:07:36 2016 -0700
>
>     mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
>
...

Thanks for trying to help! Regards!
-- 
Miroslav Rovis
Zagreb, Croatia
http://www.CroatiaFidelis.hr