From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1MfA6E-0001Ba-Pc for mharc-grub-devel@gnu.org; Sun, 23 Aug 2009 06:14:58 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MfA6C-0001Af-Ch for grub-devel@gnu.org; Sun, 23 Aug 2009 06:14:56 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MfA67-000194-Dg for grub-devel@gnu.org; Sun, 23 Aug 2009 06:14:55 -0400 Received: from [199.232.76.173] (port=57065 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MfA67-00018s-7d for grub-devel@gnu.org; Sun, 23 Aug 2009 06:14:51 -0400 Received: from xvm-190-8.ghst.net ([217.70.190.8]:37240 helo=aybabtu.com) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MfA66-0007yM-UZ for grub-devel@gnu.org; Sun, 23 Aug 2009 06:14:51 -0400 Received: from [192.168.10.10] (helo=thorin) by aybabtu.com with esmtp (Exim 4.69) (envelope-from ) id 1MfA63-0006xK-6o for grub-devel@gnu.org; Sun, 23 Aug 2009 12:14:47 +0200 Received: from rmh by thorin with local (Exim 4.69) (envelope-from ) id 1MfA62-000165-Hn for grub-devel@gnu.org; Sun, 23 Aug 2009 12:14:46 +0200 Date: Sun, 23 Aug 2009 12:14:46 +0200 From: Robert Millan To: The development of GRUB 2 Message-ID: <20090823101446.GA4130@thorin> References: <20090605173640.GW7367@riva.ucam.org> <153689213.20090605201753@gmail.com> <1248619241.25072.19.camel@fz.local> <20090820164444.GB2856@thorin> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: free as in freedom X-Message-Flag: Worried about Outlook viruses? Switch to Thunderbird! www.mozilla.com/thunderbird X-Debbugs-No-Ack: true User-Agent: Mutt/1.5.18 (2008-05-17) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) Subject: Re: Re[2]: 'password' command in GRUB 2? X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Aug 2009 10:14:56 -0000 On Fri, Aug 21, 2009 at 01:30:14PM +0200, Vladimir 'phcoder' Serbinenko wrote: > > > >> +grub_err_t > >> +grub_auth_check_authentication (const char *userlist) > >> +{ > >> +  char login[1024] = {0}; > > > > Please avoid arbitrary limits.  If the grub_cmdline_get() API is enforcing > > them, then this function is wrong and should be using malloc() instead (like, > > say, getline() or asprintf() do). > > > > If user has a username longer than 1K it can mean only that he is > trying to execute buffer overflow. Maybe. Or maybe it's just 8 bytes and we're claiming 1K of stack unnecessarily. In any case, GCS mandates that we avoid arbitrary length limits: http://www.gnu.org/prep/standards/standards.html#Semantics -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all."