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 1E0BAC33CB3 for ; Tue, 28 Jan 2020 06:08:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2DD324682 for ; Tue, 28 Jan 2020 06:08:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725880AbgA1GIl (ORCPT ); Tue, 28 Jan 2020 01:08:41 -0500 Received: from mga04.intel.com ([192.55.52.120]:47710 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725774AbgA1GIl (ORCPT ); Tue, 28 Jan 2020 01:08:41 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Jan 2020 22:08:39 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,372,1574150400"; d="scan'208";a="229190293" Received: from linux.intel.com ([10.54.29.200]) by orsmga003.jf.intel.com with ESMTP; 27 Jan 2020 22:08:39 -0800 Received: from [10.252.25.124] (abudanko-mobl.ccr.corp.intel.com [10.252.25.124]) by linux.intel.com (Postfix) with ESMTP id CEC515803C1; Mon, 27 Jan 2020 22:08:31 -0800 (PST) Subject: [PATCH v6 02/10] perf/core: open access to the core for CAP_PERFMON privileged process From: Alexey Budankov To: 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 Cc: "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 References: <74d524ab-ac11-a7b8-1052-eba10f117e09@linux.intel.com> Organization: Intel Corp. Message-ID: <6514a4b3-dfff-377a-2e89-aeb03381ab6d@linux.intel.com> Date: Tue, 28 Jan 2020 09:08:30 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <74d524ab-ac11-a7b8-1052-eba10f117e09@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: selinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Open access to monitoring of kernel code, cpus, tracepoints and namespaces data for a 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 perf_events subsystem remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure perf_events monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov --- include/linux/perf_event.h | 6 +++--- kernel/events/core.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 6d4c22aee384..730469babcc2 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1285,7 +1285,7 @@ static inline int perf_is_paranoid(void) static inline int perf_allow_kernel(struct perf_event_attr *attr) { - if (sysctl_perf_event_paranoid > 1 && !capable(CAP_SYS_ADMIN)) + if (sysctl_perf_event_paranoid > 1 && !perfmon_capable()) return -EACCES; return security_perf_event_open(attr, PERF_SECURITY_KERNEL); @@ -1293,7 +1293,7 @@ static inline int perf_allow_kernel(struct perf_event_attr *attr) static inline int perf_allow_cpu(struct perf_event_attr *attr) { - if (sysctl_perf_event_paranoid > 0 && !capable(CAP_SYS_ADMIN)) + if (sysctl_perf_event_paranoid > 0 && !perfmon_capable()) return -EACCES; return security_perf_event_open(attr, PERF_SECURITY_CPU); @@ -1301,7 +1301,7 @@ static inline int perf_allow_cpu(struct perf_event_attr *attr) static inline int perf_allow_tracepoint(struct perf_event_attr *attr) { - if (sysctl_perf_event_paranoid > -1 && !capable(CAP_SYS_ADMIN)) + if (sysctl_perf_event_paranoid > -1 && !perfmon_capable()) return -EPERM; return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT); diff --git a/kernel/events/core.c b/kernel/events/core.c index 2173c23c25b4..d956c81bd310 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11186,7 +11186,7 @@ SYSCALL_DEFINE5(perf_event_open, } if (attr.namespaces) { - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; } -- 2.20.1