From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: C file recoginzed as image file Date: Mon, 15 Jan 2007 18:27:08 -0500 Message-ID: References: <20070114025247.GB2401@kobe.laptop> Reply-To: rms@gnu.org NNTP-Posting-Host: lo.gmane.org Content-Type: text/plain; charset=ISO-8859-15 X-Trace: sea.gmane.org 1168903685 18053 80.91.229.12 (15 Jan 2007 23:28:05 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Mon, 15 Jan 2007 23:28:05 +0000 (UTC) Cc: keramida@ceid.upatras.gr, dooglus@gmail.com, c.a.rendle@gmail.com, Reiner.Steib@gmx.de, emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Jan 16 00:28:03 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1H6bF9-000158-Dk for ged-emacs-devel@m.gmane.org; Tue, 16 Jan 2007 00:27:59 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1H6bF9-0002In-9M for ged-emacs-devel@m.gmane.org; Mon, 15 Jan 2007 18:27:59 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1H6bEx-0002IE-Ss for emacs-devel@gnu.org; Mon, 15 Jan 2007 18:27:47 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1H6bEx-0002Hz-CS for emacs-devel@gnu.org; Mon, 15 Jan 2007 18:27:47 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1H6bEx-0002Hw-7c for emacs-devel@gnu.org; Mon, 15 Jan 2007 18:27:47 -0500 Original-Received: from [199.232.76.164] (helo=fencepost.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.52) id 1H6bEw-000388-Uj for emacs-devel@gnu.org; Mon, 15 Jan 2007 18:27:47 -0500 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.60) (envelope-from ) id 1H6bEK-0003ri-1W; Mon, 15 Jan 2007 18:27:08 -0500 Original-To: Stefan Monnier In-reply-to: (message from Stefan Monnier on Sun, 14 Jan 2007 20:14:43 -0500) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:65228 Archived-At: The bug in the lib may be triggered by a valid file (typically: valid but with some parameters much larger than expected). There's no evidence that our validation code wouldn't be itself vulnerable to various attacks If the checking code is thorough, checking every datum for validity before using its value, then it will not be vulnerable. The reason the libraries have vulnerabilities is that their authors are thinking about displaying a valid image, rather than detecting an invalid one. The point about failures on valid images is a valid point, but I don't see what we can do about it at this level. Perfection is not attainable. Anyway, those bugs are likely to be found and fixed because they would fail on real images.