linux-kernel - Re: Urgent: x86-32 and GNU ld 2.22.52.0.1

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CA+5PVA6n5tJ4tox56ntrJ3T+KgZXnbxpYXjyc5_D9tQ7raQFHw@mail.gmail.com>
Date:	Fri, 18 May 2012 12:55:51 -0400
From:	Josh Boyer <jwboyer@...il.com>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	"H.J. Lu" <hjl.tools@...il.com>, Ingo Molnar <mingo@...e.hu>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Greg KH <gregkh@...e.de>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Jarkko Sakkinen <jarkko.sakkinen@...el.com>
Subject: Re: Urgent: x86-32 and GNU ld 2.22.52.0.1

On Fri, May 18, 2012 at 12:20 PM, H. Peter Anvin <hpa@...or.com> wrote:
> On 05/18/2012 09:14 AM, H.J. Lu wrote:
>> On Fri, May 18, 2012 at 8:56 AM, H. Peter Anvin <hpa@...or.com> wrote:
>>> I need an urgent opinion.  It seems we have an epic mess on our hands.
>>>
>>> GNU ld 2.22.52.0.1 silently changed the semantics of section-relative
>>> symbols that are part of otherwise empty sections, and silently changes
>>> them to absolute.  We rely on section-relative symbols staying
>>> section-relative, and actually have several sections in the linker
>>> script solely for this purpose.
>>
>> That is I talked to you a couple days ago:
>>
>> http://sourceware.org/bugzilla/show_bug.cgi?id=14052
>>
>
> I know, which was a very good thing... otherwise we'd probably not have
> tracked this down anywhere near as quickly.  Thank you.
>
> The problem is that this version of binutils made it into Fedora 17, and
> so we now have a large number of users with a known bad binutils in the
> field...

We've not seen many kernel bugs that would seem to be blamed on this as
of yet.  It does seem like a problem waiting to hit us once F17 goes GA
though.  My limited 32-bit F17 machine collection definitely shows the
__init_{begin,end} symbols being absolute, but they boot fine.  Likely
because the kernel isn't relocated on them.

For what it's worth, I've filed a bug against Fedora binutils here:
https://bugzilla.redhat.com/show_bug.cgi?id=822981

josh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/