From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756619Ab2CLTKE (ORCPT ); Mon, 12 Mar 2012 15:10:04 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:53327 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755891Ab2CLTJ7 (ORCPT ); Mon, 12 Mar 2012 15:09:59 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Djalal Harouni Cc: linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, Andrew Morton , Linus Torvalds , Al Viro , Alexey Dobriyan , Vasiliy Kulikov , Kees Cook , Solar Designer , WANG Cong , James Morris , Oleg Nesterov , linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, Alan Cox , Greg KH , Ingo Molnar , Stephen Wilson , "Jason A. Donenfeld" References: <1331421919-15499-1-git-send-email-tixxdz@opendz.org> Date: Mon, 12 Mar 2012 12:13:15 -0700 In-Reply-To: <1331421919-15499-1-git-send-email-tixxdz@opendz.org> (Djalal Harouni's message of "Sun, 11 Mar 2012 00:25:10 +0100") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=98.207.153.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19zQAj+8D8fmMwWv4eibXsCLNqlKRM4iyA= X-SA-Exim-Connect-IP: 98.207.153.68 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Djalal Harouni X-Spam-Relay-Country: ** Subject: Re: [PATCH 0/9] proc: protect /proc//* files across execve X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Djalal Harouni writes: > Procfs files and other important objects may contain sensitive information > which must not be seen, inherited or processed across execve. So I am dense. /proc//mem was special in that it uses a different set of checks than other files, and to do those access checks /proc//mem needed to look at exec_id. For all of the access checks that are not written in that silly way. What is wrong with ptrace_may_access run at every read/write of a file? We redo all of the permission checks every time so that should avoid races. I really think you are trying to solve something that is not broken. Certainly I could not see your argument for why anything but /proc//mem needs attention. Eric