From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8B1EC2D0DB for ; Tue, 28 Jan 2020 21:21:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B575C207FD for ; Tue, 28 Jan 2020 21:21:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726428AbgA1VVF (ORCPT ); Tue, 28 Jan 2020 16:21:05 -0500 Received: from namei.org ([65.99.196.166]:60568 "EHLO namei.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726211AbgA1VVF (ORCPT ); Tue, 28 Jan 2020 16:21:05 -0500 Received: from localhost (localhost [127.0.0.1]) by namei.org (8.14.4/8.14.4) with ESMTP id 00SLIGx1004605; Tue, 28 Jan 2020 21:18:16 GMT Date: Wed, 29 Jan 2020 08:18:16 +1100 (AEDT) From: James Morris To: Alexey Budankov cc: Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "benh@kernel.crashing.org" , Paul Mackerras , Michael Ellerman , "james.bottomley@hansenpartnership.com" , Serge Hallyn , Will Deacon , Robert Richter , Alexei Starovoitov , "intel-gfx@lists.freedesktop.org" , Jiri Olsa , Andi Kleen , Stephane Eranian , Igor Lubashev , Alexander Shishkin , Namhyung Kim , Song Liu , Lionel Landwerlin , linux-kernel , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , linux-arm-kernel , "linuxppc-dev@lists.ozlabs.org" , "linux-parisc@vger.kernel.org" , "linux-perf-users@vger.kernel.org" , oprofile-list@lists.sf.net Subject: Re: [PATCH v6 10/10] drivers/oprofile: open access for CAP_PERFMON privileged process In-Reply-To: Message-ID: References: <74d524ab-ac11-a7b8-1052-eba10f117e09@linux.intel.com> User-Agent: Alpine 2.21 (LRH 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Tue, 28 Jan 2020, Alexey Budankov wrote: > > Open access to monitoring for CAP_PERFMON privileged process. Providing > the access under CAP_PERFMON capability singly, without the rest of > CAP_SYS_ADMIN credentials, excludes chances to misuse the credentials and > makes operation more secure. > > CAP_PERFMON implements the principal of least privilege for performance > monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39 principle > of least privilege: A security design principle that states that a process > or program be granted only those privileges (e.g., capabilities) necessary > to accomplish its legitimate function, and only for the time that such > privileges are actually required) > > For backward compatibility reasons access to the monitoring remains open > for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure > monitoring is discouraged with respect to CAP_PERFMON capability. > > Signed-off-by: Alexey Budankov > --- > drivers/oprofile/event_buffer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Acked-by: James Morris > > diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c > index 12ea4a4ad607..6c9edc8bbc95 100644 > --- a/drivers/oprofile/event_buffer.c > +++ b/drivers/oprofile/event_buffer.c > @@ -113,7 +113,7 @@ static int event_buffer_open(struct inode *inode, struct file *file) > { > int err = -EPERM; > > - if (!capable(CAP_SYS_ADMIN)) > + if (!perfmon_capable()) > return -EPERM; > > if (test_and_set_bit_lock(0, &buffer_opened)) > -- James Morris