Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753505Ab2HCNHs (ORCPT ); Fri, 3 Aug 2012 09:07:48 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:45909 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752976Ab2HCNHp convert rfc822-to-8bit (ORCPT ); Fri, 3 Aug 2012 09:07:45 -0400 References: <1343991184-3619-1-git-send-email-berrange@redhat.com> <20120803125210.GD12870@redhat.com> User-Agent: K-9 Mail for Android In-Reply-To: <20120803125210.GD12870@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: "Eric W. Biederman" Date: Fri, 03 Aug 2012 06:07:36 -0700 To: "Daniel P. Berrange" CC: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, Serge Hallyn , Daniel Lezcano , Michael Kerrisk , Tejun Heo , Oleg Nesterov Message-ID: Content-Transfer-Encoding: 8BIT X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=98.207.153.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX196v8bslMbW/glsLBDdA/jShGwIXT2GvuI= X-SA-Exim-Connect-IP: 98.207.153.68 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * 0.1 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -0.0 BAYES_40 BODY: Bayes spam probability is 20 to 40% * [score: 0.3029] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_XMDrugObfuBody_08 obfuscated drug references * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.0 T_XMDrugObfuBody_04 obfuscated drug references X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;"Daniel P. Berrange" X-Spam-Relay-Country: Subject: Re: [PATCH] Forbid invocation of kexec_load() outside initial PID namespace 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 Content-Length: 1177 Lines: 31 "Daniel P. Berrange" wrote: >On Fri, Aug 03, 2012 at 05:45:40AM -0700, Eric W. Biederman wrote: >> The solution is to use user namespaces and to only test ns_capable on >the magic reboot path. >> >> For the 3.7 timeframe that should be a realistic solution. > >Hmm, that would imply that if LXC wants to allow reboot()/CAP_SYS_BOOT >they will be forced to use CLONE_NEWUSER. I was rather looking for a >way >to allow the container to keep CAP_SYS_BOOT, without also mandating use >of user namespaces. If we remove the use of CAP_SYS_BOOT on the container reboot path perhaps. But you have hit one small issue in the huge pile of issues why giving contaners capabilities is generally a bad idea. This is the reason I have been insisting on a reasonable version of user namespaces for a long time. When the security issues become important it is time for user namespaces. That is their purpose. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/