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, URIBL_BLOCKED,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 48054C43331 for ; Thu, 2 Apr 2020 08:47:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28702208E4 for ; Thu, 2 Apr 2020 08:47:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387783AbgDBIrI (ORCPT ); Thu, 2 Apr 2020 04:47:08 -0400 Received: from mga12.intel.com ([192.55.52.136]:8925 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728612AbgDBIrI (ORCPT ); Thu, 2 Apr 2020 04:47:08 -0400 IronPort-SDR: 4vbGSjMO6dritYfBjM6LxmYRM7yOgdqyNJ7RkBJvNE+xdTkVriYs2L9Vwkoug80Jgcfy/2AB6l 19nmj9Isq4rg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2020 01:47:07 -0700 IronPort-SDR: 7tJLumpdWYlkcHYhVh+R3ZpZwhs962ucUkWwav961GZbQ6z8behCfxQAdYKbhRUR6299u21Aok UYT0iKhJujpw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,335,1580803200"; d="scan'208";a="242465231" Received: from linux.intel.com ([10.54.29.200]) by fmsmga008.fm.intel.com with ESMTP; 02 Apr 2020 01:47:07 -0700 Received: from [10.249.226.252] (abudanko-mobl.ccr.corp.intel.com [10.249.226.252]) by linux.intel.com (Postfix) with ESMTP id 75565580544; Thu, 2 Apr 2020 01:47:02 -0700 (PDT) Subject: [PATCH v8 03/12] perf/core: open access to probes for CAP_PERFMON privileged process From: Alexey Budankov To: Peter Zijlstra , Arnaldo Carvalho de Melo , Alexei Starovoitov , Ingo Molnar , James Morris , Namhyung Kim Cc: Serge Hallyn , Jiri Olsa , Song Liu , Andi Kleen , Stephane Eranian , Igor Lubashev , Thomas Gleixner , linux-kernel , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , "intel-gfx@lists.freedesktop.org" , "linux-doc@vger.kernel.org" , linux-man@vger.kernel.org References: Organization: Intel Corp. Message-ID: <3c129d9a-ba8a-3483-ecc5-ad6c8e7c203f@linux.intel.com> Date: Thu, 2 Apr 2020 11:47:01 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org Open access to monitoring via kprobes and uprobes and eBPF tracing 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. perf kprobes and uprobes are used by ftrace and eBPF. perf probe uses ftrace to define new kprobe events, and those events are treated as tracepoint events. eBPF defines new probes via perf_event_open interface and then the probes are used in eBPF tracing. 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 Acked-by: James Morris Reviewed-by: James Morris --- kernel/events/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 2af0f4557b63..364c233c3f25 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9259,7 +9259,7 @@ static int perf_kprobe_event_init(struct perf_event *event) if (event->attr.type != perf_kprobe.type) return -ENOENT; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; /* @@ -9319,7 +9319,7 @@ static int perf_uprobe_event_init(struct perf_event *event) if (event->attr.type != perf_uprobe.type) return -ENOENT; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; /* -- 2.24.1