Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754951AbaDYUU6 (ORCPT ); Fri, 25 Apr 2014 16:20:58 -0400 Received: from mail-wg0-f50.google.com ([74.125.82.50]:51157 "EHLO mail-wg0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753038AbaDYUUz (ORCPT ); Fri, 25 Apr 2014 16:20:55 -0400 MIME-Version: 1.0 In-Reply-To: <20140425200156.GA13727@redhat.com> References: <535A5C78.1070901@samsung.com> <535A75C1.3050901@samsung.com> <20140425182310.GA9128@redhat.com> <87sip15iy5.fsf@x220.int.ebiederm.org> <20140425192543.GA11908@redhat.com> <878uqt42q7.fsf@x220.int.ebiederm.org> <20140425200156.GA13727@redhat.com> Date: Fri, 25 Apr 2014 23:20:54 +0300 Message-ID: Subject: Re: Kernel panic at Ubuntu: IMA + Apparmor From: Dmitry Kasatkin To: Oleg Nesterov Cc: "Eric W. Biederman" , Dmitry Kasatkin , linux-security-module , John Johansen , Mimi Zohar , James Morris , viro@zeniv.linux.org.uk, Linux Kernel Mailing List , kernel-team 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 25 April 2014 23:01, Oleg Nesterov wrote: > On 04/25, Eric W. Biederman wrote: >> >> Oleg Nesterov writes: >> >> > Well. I _think_ that __fput() and ima_file_free() in particular should not >> > depend on current and/or current->nsproxy. If nothing else, fput() can be >> > called by the unrelated task which looks into /proc/pid/. >> > >> > But again, task_work_add() has more and more users, and it seems that even >> > __fput() paths can do "everything", so perhaps it would be safer to allow >> > to use ->nsproxy in task_work_run. >> >> Like I said, give me a clear motivating case. > > I agree, we need a reason. Currently I do not see one. > >> Right now not allowing >> nsproxy is turning up bugs in __fput. Which seems like a good thing. > > This is what I certainly agree with ;) > Hi, IMA uses kernel_read API which does not know anything about caller. And of course security frameworks are at guard as usual. Exactly after reading first Eric's respons, I thought why to scratch the head when task work queues are indeed designed for tasks... And if you to dig for the history, IMA-appraisal was stuck due to lockdep reporting even though it was on non-everlaping cases. IIRC files vs. directories... After that IIRC Al Viro discussed about delayed fput and IIRC Oleg (sorry if I am wrong) introduced task work queues. So IMA-appraisal was able to be upstreamed... That was ~3.4 time frame, IIRC Name space also dated around ~3.4?? Apparmor namespace change was also around that time. 3.10 introduces this name space order change and broke IMA-appraisal. Isn't it a clear motivating case??? - Dmitry > Oleg. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Thanks, Dmitry -- 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/