From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752699Ab2GZRDk (ORCPT ); Thu, 26 Jul 2012 13:03:40 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:49166 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545Ab2GZRDi (ORCPT ); Thu, 26 Jul 2012 13:03:38 -0400 Date: Thu, 26 Jul 2012 18:07:09 +0100 From: Alan Cox To: Anton Vorontsov Cc: Jason Wessel , Andrew Morton , Steven Rostedt , John Stultz , arve@android.com, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com, kgdb-bugreport@lists.sourceforge.net Subject: Re: [PATCH 6/7] kdb: Mark safe commands as KDB_SAFE and KDB_SAFE_NO_ARGS Message-ID: <20120726180709.09777a3b@pyramind.ukuu.org.uk> In-Reply-To: <1343312791-9138-6-git-send-email-anton.vorontsov@linaro.org> References: <20120726142514.GA32158@lizard> <1343312791-9138-6-git-send-email-anton.vorontsov@linaro.org> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > The following commands were marked as "safe": > > Clear Breakpoint > Enable Breakpoint > Disable Breakpoint > Display exception frame > Stack traceback This is sufficient to steal cryptographic keys in many environments. In fact you merely need two or three breakpoints and to log the order they are hit through the crypto computation. > Display stack for process Exposes all sorts of user data unless you mean just the call trace, in which case it's still quite useful. > Display stack all processes Ditto > Send a signal to a process Like say sending SIGSTOP to security monitoring threads or the battery manager on locked devices that rely on software battery management ? It's an interesting idea but you need almost nothing to extract keys from a system or to subvert it. Alan