From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757610Ab3APWfw (ORCPT ); Wed, 16 Jan 2013 17:35:52 -0500 Received: from e8.ny.us.ibm.com ([32.97.182.138]:56690 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756310Ab3APWfv (ORCPT ); Wed, 16 Jan 2013 17:35:51 -0500 Message-ID: <1358375723.4593.206.camel@falcor1> Subject: Re: [PATCH 2/3] binfmt_elf: Verify signature of signed elf binary From: Mimi Zohar To: Vivek Goyal Cc: linux-kernel@vger.kernel.org, ebiederm@xmission.com, pjones@redhat.com, hpa@zytor.com, dhowells@redhat.com, jwboyer@redhat.com, Dmitry Kasatkin , linux-security-module Date: Wed, 16 Jan 2013 17:35:23 -0500 In-Reply-To: <1358285695-26173-3-git-send-email-vgoyal@redhat.com> References: <1358285695-26173-1-git-send-email-vgoyal@redhat.com> <1358285695-26173-3-git-send-email-vgoyal@redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 (3.2.3-3.fc16) Content-Transfer-Encoding: 7bit Mime-Version: 1.0 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13011622-9360-0000-0000-00000F4C5EE7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2013-01-15 at 16:34 -0500, Vivek Goyal wrote: > If a binary is signed, verify its signature. If signature is not valid, do > not allow execution. If binary is not signed, execution is allowed > unconditionally. Basically you're building the policy into the executable. Anyone can rebuild the executable and, without signing it, install/replace an existing one. How is this safe? The signature verification policy needs to be defined independently of the executable. Mimi