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Date: Wed, 26 Oct 2016 16:25:50 +0300
From: Konstantin Belousov <kostikbel@gmail.com>
To: Tijl Coosemans <tijl@FreeBSD.org>
Cc: Gleb Smirnoff <glebius@FreeBSD.org>, src-committers@freebsd.org,
 svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject: Re: svn commit: r307936 - head/sys/amd64/amd64
Message-ID: <20161026132550.GV54029@kib.kiev.ua>
References: <201610251713.u9PHDkq2076226@repo.freebsd.org>
 <20161025212600.36e91455@kalimero.tijl.coosemans.org>
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On Tue, Oct 25, 2016 at 09:26:00PM +0200, Tijl Coosemans wrote:
> On Tue, 25 Oct 2016 17:13:46 +0000 (UTC) Gleb Smirnoff <glebius@FreeBSD.org> wrote:
> > Author: glebius
> > Date: Tue Oct 25 17:13:46 2016
> > New Revision: 307936
> > URL: https://svnweb.freebsd.org/changeset/base/307936
> > 
> > Log:
> >   The argument validation in r296956 was not enough to close all possible
> >   overflows in sysarch(2).
> >   
> >   Submitted by:	Kun Yang <kun.yang chaitin.com>
> >   Patch by:	kib
> >   Security:	SA-16:15
> > 
> > Modified:
> >   head/sys/amd64/amd64/sys_machdep.c
> 
> This patch and r296956 need to be applied to i386 too, don't they?
I do not think so.  The amd64 bug is that I thought that the overflow
checks were not needed, which appeared to be not true.

i386_set_ldt(), which is the i386 version of amd64_set_ldt(), already
contained the comparisions of largest_ld with pldt->ldt_len etc.

Still, independend look at the i386 (and amd64 version as well) is more
than welcomed, so please read the code yourself.