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_PASS, USER_AGENT_SANE_1 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 AB238C433DB for ; Thu, 4 Feb 2021 20:48:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E898264F5E for ; Thu, 4 Feb 2021 20:48:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E898264F5E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ucw.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5B7366B0005; Thu, 4 Feb 2021 15:48:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 53FFF6B0006; Thu, 4 Feb 2021 15:48:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 42FCC6B006E; Thu, 4 Feb 2021 15:48:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0120.hostedemail.com [216.40.44.120]) by kanga.kvack.org (Postfix) with ESMTP id 2A75E6B0005 for ; Thu, 4 Feb 2021 15:48:40 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id DE2FD180AD801 for ; Thu, 4 Feb 2021 20:48:39 +0000 (UTC) X-FDA: 77781773958.17.hill63_3108bda275df Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id C379A180D0181 for ; Thu, 4 Feb 2021 20:48:39 +0000 (UTC) X-HE-Tag: hill63_3108bda275df X-Filterd-Recvd-Size: 2526 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) by imf44.hostedemail.com (Postfix) with ESMTP for ; Thu, 4 Feb 2021 20:48:39 +0000 (UTC) Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 782BA1C0B77; Thu, 4 Feb 2021 21:48:36 +0100 (CET) Date: Thu, 4 Feb 2021 21:48:35 +0100 From: Pavel Machek To: Timur Tabi Cc: Petr Mladek , Steven Rostedt , 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, keescook@chromium.org, john.ogness@linutronix.de, akinobu.mita@gmail.com Subject: Re: [PATCH] lib/vsprintf: make-printk-non-secret printks all addresses as unhashed Message-ID: <20210204204835.GA7529@amd> References: <20210202201846.716915-1-timur@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="1yeeQ81UyVL57Vl7" Content-Disposition: inline In-Reply-To: <20210202201846.716915-1-timur@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) 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: --1yeeQ81UyVL57Vl7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue 2021-02-02 14:18:46, Timur Tabi wrote: > If the make-printk-non-secret command-line parameter is set, then > printk("%p") will print addresses as unhashed. This is useful for > debugging purposes. >=20 > 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. Yes please. I needed to see pointers for debugging, and seeing hashed pointers is nasty. Having to patch C code to be able to develop... is bad. > + pr_warn("** Kernel memory addresses are exposed, which may **\n"); > + pr_warn("** compromise security on your system. **\n"); This is lies, right? And way too verbose. Pavel --=20 http://www.livejournal.com/~pavelmachek --1yeeQ81UyVL57Vl7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAmAcXaMACgkQMOfwapXb+vKvOQCeNeIzhzv70yiBaBw63hsqyL7n Bm0An3ALaR2Z9WS8hhX/DU42VPs9cxmx =lE4c -----END PGP SIGNATURE----- --1yeeQ81UyVL57Vl7--