From owner-freebsd-security@FreeBSD.ORG Tue Jun 20 17:44:01 2006 Return-Path: X-Original-To: freebsd-security@freebsd.org Delivered-To: freebsd-security@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8461D16A474; Tue, 20 Jun 2006 17:44:01 +0000 (UTC) (envelope-from jasone@FreeBSD.org) Received: from lh.synack.net (lh.synack.net [204.152.188.37]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2A9BA43D46; Tue, 20 Jun 2006 17:44:01 +0000 (GMT) (envelope-from jasone@FreeBSD.org) Received: by lh.synack.net (Postfix, from userid 100) id 00C095E4919; Tue, 20 Jun 2006 10:44:00 -0700 (PDT) Received: from [192.168.168.201] (70-37-200-108.losaca.adelphia.net [70.37.200.108]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lh.synack.net (Postfix) with ESMTP id 9042C5E4912; Tue, 20 Jun 2006 10:43:59 -0700 (PDT) Message-ID: <449833DD.70904@FreeBSD.org> Date: Tue, 20 Jun 2006 10:43:57 -0700 From: Jason Evans User-Agent: Mozilla Thunderbird 1.0.8-1.4.1 (X11/20060420) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Giorgos Keramidas References: <20060618203903.31161.qmail@web30306.mail.mud.yahoo.com> <44967861.6070509@obluda.cz> <20060620125350.10d0c9ef.nick@nickwithers.com> <44980ECC.5000607@obluda.cz> <20060620170353.GB90842@gothmog.pc> In-Reply-To: <20060620170353.GB90842@gothmog.pc> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 3.0.6 (2005-12-07) on lh.synack.net X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=failed version=3.0.6 X-Mailman-Approved-At: Wed, 21 Jun 2006 02:00:55 +0000 Cc: Dan Lukes , freebsd-security@freebsd.org Subject: Re: memory pages nulling when releasing X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Jun 2006 17:44:01 -0000 Giorgos Keramidas wrote: > On 2006-06-20 17:05, Dan Lukes wrote: > >>>There's "Z" malloc option that's used to initialise page with zeros >>>instead of 0xd0 >> >>Difference betwen Z and J isn't the fill value only. Z apply >>for allocations of new memory (when imalloc() called); J apply >>on changes in allocated block size (e.g. realloc) and free. So >>'Z' doesn't "zero on free" but "zero on alloc". Well, things >>aren't simple as Z implies J ... >> >>BTW, Z nor J doesn't imply 'R' despite of text of manual page. > > > Are you sure? Then we should fix the manpage. > Cc'ing Jason Evans, who may be interested too. The man page looks accurate to me. What aspect of the descriptions of 'J' and 'Z' do you think is incorrect? Thanks, Jason