From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751813AbdLKT7f (ORCPT ); Mon, 11 Dec 2017 14:59:35 -0500 Received: from mail-vk0-f41.google.com ([209.85.213.41]:42559 "EHLO mail-vk0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725AbdLKT7c (ORCPT ); Mon, 11 Dec 2017 14:59:32 -0500 X-Google-Smtp-Source: ACJfBosEDMrjfNWo5mPhPgu9XSzUyStEB5qme/VKSS6q8grnYM/rEs9P4EdPkbxvOrTQITSF1XoMr1O2UKsEq1U0jT4= MIME-Version: 1.0 In-Reply-To: <20171210214753.GM7829@linux.vnet.ibm.com> References: <20171201200819.GA25519@linux.vnet.ibm.com> <1512158945-27269-2-git-send-email-paulmck@linux.vnet.ibm.com> <20171204134203.GR7829@linux.vnet.ibm.com> <20171204161100.GT7829@linux.vnet.ibm.com> <20171210214753.GM7829@linux.vnet.ibm.com> From: Kees Cook Date: Mon, 11 Dec 2017 11:59:30 -0800 X-Google-Sender-Auth: 1V6ma-MZkpUmEyYvG6Wxqa1I0B8 Message-ID: Subject: Re: [PATCH tip/core/rcu 02/20] torture: Prepare scripting for shift from %p to %pK To: "Paul E. McKenney" Cc: Linus Torvalds , Andy Shevchenko , David Laight , "linux-kernel@vger.kernel.org" , "mingo@kernel.org" , "jiangshanlai@gmail.com" , "dipankar@in.ibm.com" , "akpm@linux-foundation.org" , "mathieu.desnoyers@efficios.com" , "josh@joshtriplett.org" , "tglx@linutronix.de" , "peterz@infradead.org" , "rostedt@goodmis.org" , "dhowells@redhat.com" , "edumazet@google.com" , "fweisbec@gmail.com" , "oleg@redhat.com" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 10, 2017 at 1:47 PM, Paul E. McKenney wrote: > On Sun, Dec 10, 2017 at 12:39:11PM -0800, Linus Torvalds wrote: >> I'd rather make %pK act more like %p than have gratuitous differences. The feature that paranoid folks currently depend on is getting a value entirely zeroed out with %pK (which is the least possible info leak risk). The hashed %p is almost just as good except that identical hashes are still usable to confirm matching values (but the cases where this would be useful to an attacker are hopefully approaching zero). > So it looks like I should drop the three patches in my tree that convert > %p to %pK. > > Any objections? Sounds good. If they're still useful when hashed, keep the %p. If you want to remove them because they're sensitive, just remove them instead of adding new %pK users. -Kees -- Kees Cook Pixel Security