From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 17 May 2011 14:57:40 +0200 (CEST) Received: from mx2.mail.elte.hu ([157.181.151.9]:49902 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1490989Ab1EQM5f (ORCPT ); Tue, 17 May 2011 14:57:35 +0200 Received: from elvis.elte.hu ([157.181.1.14]) by mx2.mail.elte.hu with esmtp (Exim) id 1QMJpf-0002NF-Ma from ; Tue, 17 May 2011 14:57:09 +0200 Received: by elvis.elte.hu (Postfix, from userid 1004) id 616503E2533; Tue, 17 May 2011 14:56:57 +0200 (CEST) Date: Tue, 17 May 2011 14:57:00 +0200 From: Ingo Molnar To: Will Drewry Cc: Eric Paris , James Morris , linux-kernel@vger.kernel.org, Steven Rostedt , Frederic Weisbecker , kees.cook@canonical.com, agl@chromium.org, Peter Zijlstra , "Serge E. Hallyn" , Ingo Molnar , Andrew Morton , Tejun Heo , Michal Marek , Oleg Nesterov , Jiri Slaby , David Howells , Russell King , Michal Simek , Ralf Baechle , Benjamin Herrenschmidt , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com, Paul Mundt , "David S. Miller" , Thomas Gleixner , "H. Peter Anvin" , x86@kernel.org, Peter Zijlstra , linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, Linus Torvalds Subject: Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering Message-ID: <20110517125700.GD21441@elte.hu> References: <20110512074850.GA9937@elte.hu> <20110512130104.GA2912@elte.hu> <20110513121034.GG21022@elte.hu> <1305299455.2076.26.camel@localhost.localdomain> <20110514073015.GB9307@elte.hu> <20110516124304.GC7128@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) Received-SPF: neutral (mx2.mail.elte.hu: 157.181.1.14 is neither permitted nor denied by domain of elte.hu) client-ip=157.181.1.14; envelope-from=mingo@elte.hu; helo=elvis.elte.hu; X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 30062 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: mingo@elte.hu Precedence: bulk X-list: linux-mips * Will Drewry wrote: > > This is *far* more generic still yields the same short-term end result as > > far as your sandboxing is concerned. > > Almost :/ [...] Hey that's a pretty good result from a subsystem that was not written with your usecase in mind *at all* ;-) > [...] I still need to review the code you've pointed out, but, at present, > the ftrace hooks occur after the seccomp and syscall auditing hooks. This > means that that code is exposed no matter what in this model. To trim the > exposed surface to userspace, we really need those early hooks. While I can > see both hacky and less hacky approaches around this, it stills strikes me > that the seccomp thread flag and early interception are good to reuse. One > option might be to allow seccomp to be a secure-syscall event source, but I > suspect that lands more on the hack-y side of the fence :) Agreed, there should be no security compromise imposed on your usecase, at all. You could move the event callback sooner into the syscall-entry sequence to make sure it's the highest priority thing to process? There's no semantic dependency on its current location so this can be changed AFAICS. Thanks, Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.mail.elte.hu (mx2.mail.elte.hu [157.181.151.9]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5CE3FB6EF7 for ; Tue, 17 May 2011 22:57:35 +1000 (EST) Date: Tue, 17 May 2011 14:57:00 +0200 From: Ingo Molnar To: Will Drewry Subject: Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering Message-ID: <20110517125700.GD21441@elte.hu> References: <20110512074850.GA9937@elte.hu> <20110512130104.GA2912@elte.hu> <20110513121034.GG21022@elte.hu> <1305299455.2076.26.camel@localhost.localdomain> <20110514073015.GB9307@elte.hu> <20110516124304.GC7128@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: linux-mips@linux-mips.org, linux-sh@vger.kernel.org, Peter Zijlstra , Frederic Weisbecker , Heiko Carstens , Oleg Nesterov , David Howells , Paul Mackerras , Eric Paris , "H. Peter Anvin" , sparclinux@vger.kernel.org, Jiri Slaby , linux-s390@vger.kernel.org, Russell King , x86@kernel.org, James Morris , Linus Torvalds , Ingo Molnar , kees.cook@canonical.com, "Serge E. Hallyn" , Peter Zijlstra , Steven Rostedt , Tejun Heo , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Michal Marek , Michal Simek , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Ralf Baechle , Paul Mundt , Martin Schwidefsky , linux390@de.ibm.com, Andrew Morton , agl@chromium.org, "David S. Miller" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , * Will Drewry wrote: > > This is *far* more generic still yields the same short-term end result as > > far as your sandboxing is concerned. > > Almost :/ [...] Hey that's a pretty good result from a subsystem that was not written with your usecase in mind *at all* ;-) > [...] I still need to review the code you've pointed out, but, at present, > the ftrace hooks occur after the seccomp and syscall auditing hooks. This > means that that code is exposed no matter what in this model. To trim the > exposed surface to userspace, we really need those early hooks. While I can > see both hacky and less hacky approaches around this, it stills strikes me > that the seccomp thread flag and early interception are good to reuse. One > option might be to allow seccomp to be a secure-syscall event source, but I > suspect that lands more on the hack-y side of the fence :) Agreed, there should be no security compromise imposed on your usecase, at all. You could move the event callback sooner into the syscall-entry sequence to make sure it's the highest priority thing to process? There's no semantic dependency on its current location so this can be changed AFAICS. Thanks, Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 From: mingo@elte.hu (Ingo Molnar) Date: Tue, 17 May 2011 14:57:00 +0200 Subject: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering In-Reply-To: References: <20110512074850.GA9937@elte.hu> <20110512130104.GA2912@elte.hu> <20110513121034.GG21022@elte.hu> <1305299455.2076.26.camel@localhost.localdomain> <20110514073015.GB9307@elte.hu> <20110516124304.GC7128@elte.hu> Message-ID: <20110517125700.GD21441@elte.hu> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * Will Drewry wrote: > > This is *far* more generic still yields the same short-term end result as > > far as your sandboxing is concerned. > > Almost :/ [...] Hey that's a pretty good result from a subsystem that was not written with your usecase in mind *at all* ;-) > [...] I still need to review the code you've pointed out, but, at present, > the ftrace hooks occur after the seccomp and syscall auditing hooks. This > means that that code is exposed no matter what in this model. To trim the > exposed surface to userspace, we really need those early hooks. While I can > see both hacky and less hacky approaches around this, it stills strikes me > that the seccomp thread flag and early interception are good to reuse. One > option might be to allow seccomp to be a secure-syscall event source, but I > suspect that lands more on the hack-y side of the fence :) Agreed, there should be no security compromise imposed on your usecase, at all. You could move the event callback sooner into the syscall-entry sequence to make sure it's the highest priority thing to process? There's no semantic dependency on its current location so this can be changed AFAICS. Thanks, Ingo