From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE, USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 574C4C433E0 for ; Tue, 2 Feb 2021 22:34:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B783864F91 for ; Tue, 2 Feb 2021 22:34:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B783864F91 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5051F6B0006; Tue, 2 Feb 2021 17:34:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 48DB76B006C; Tue, 2 Feb 2021 17:34:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3561A6B006E; Tue, 2 Feb 2021 17:34:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0101.hostedemail.com [216.40.44.101]) by kanga.kvack.org (Postfix) with ESMTP id 194F26B0006 for ; Tue, 2 Feb 2021 17:34:41 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D712F8249980 for ; Tue, 2 Feb 2021 22:34:40 +0000 (UTC) X-FDA: 77774783520.11.tent13_4f0dca5275ce Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id B969D180F8B82 for ; Tue, 2 Feb 2021 22:34:40 +0000 (UTC) X-HE-Tag: tent13_4f0dca5275ce X-Filterd-Recvd-Size: 2476 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf46.hostedemail.com (Postfix) with ESMTP for ; Tue, 2 Feb 2021 22:34:40 +0000 (UTC) Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2DC9F64F63; Tue, 2 Feb 2021 22:34:38 +0000 (UTC) Date: Tue, 2 Feb 2021 17:34:36 -0500 From: Steven Rostedt To: Timur Tabi Cc: Kees Cook , Petr Mladek , Sergey Senozhatsky , linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org, akpm@linux-foundation.org, torvalds@linux-foundation.org, roman.fietze@magna.com, john.ogness@linutronix.de, akinobu.mita@gmail.com Subject: Re: [PATCH] lib/vsprintf: make-printk-non-secret printks all addresses as unhashed Message-ID: <20210202173436.6516c676@gandalf.local.home> In-Reply-To: <9ce56a1c-9ea6-996b-84c6-cfde908c2ecd@kernel.org> References: <20210202201846.716915-1-timur@kernel.org> <202102021351.AEDE896AB3@keescook> <9ce56a1c-9ea6-996b-84c6-cfde908c2ecd@kernel.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 2 Feb 2021 16:19:20 -0600 Timur Tabi wrote: > On 2/2/21 3:52 PM, Kees Cook wrote: > >> A large warning message is displayed if this option is enabled, > >> because unhashed addresses, while useful for debugging, exposes > >> kernel addresses which can be a security risk. > > > Linus has expressly said "no" to things like this in the past: > > https://lore.kernel.org/lkml/CA+55aFwieC1-nAs+NFq9RTwaR8ef9hWa4MjNBWL41F-8wM49eA@mail.gmail.com/ > Maybe I misunderstood, but I thought this is what Vlastimil, Petr, > Sergey, John, and Steven asked for. Maybe Linus changed his mind since then? "I also suspect that everybody has already accepted that KASLR isn't really working locally anyway (due to all the hw leak models with cache and TLB timing), so anybody who can look at kernel messages already probably could figure most of those things out." https://lore.kernel.org/r/CAHk-=wjnEV2E6vCRxv5S5m27iOjHeVWNbfK=JV8qxot4Do-FgA@mail.gmail.com -- Steve