From patchwork Mon Feb 17 08:07:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Budankov X-Patchwork-Id: 11385555 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E8BE31820 for ; Mon, 17 Feb 2020 08:07:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D3A7420725 for ; Mon, 17 Feb 2020 08:07:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727233AbgBQIHp (ORCPT ); Mon, 17 Feb 2020 03:07:45 -0500 Received: from mga03.intel.com ([134.134.136.65]:29037 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726996AbgBQIHp (ORCPT ); Mon, 17 Feb 2020 03:07:45 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Feb 2020 00:07:44 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,451,1574150400"; d="scan'208";a="314705824" Received: from linux.intel.com ([10.54.29.200]) by orsmga001.jf.intel.com with ESMTP; 17 Feb 2020 00:07:44 -0800 Received: from [10.125.252.180] (abudanko-mobl.ccr.corp.intel.com [10.125.252.180]) by linux.intel.com (Postfix) with ESMTP id 27D7258052E; Mon, 17 Feb 2020 00:07:37 -0800 (PST) Subject: [PATCH v7 03/12] perf/core: open access to probes for CAP_PERFMON privileged process From: Alexey Budankov To: James Morris , Serge Hallyn , Stephen Smalley , Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "joonas.lahtinen@linux.intel.com" , Alexei Starovoitov , Will Deacon , Paul Mackerras , Helge Deller , Thomas Gleixner Cc: Andi Kleen , Stephane Eranian , Igor Lubashev , Jiri Olsa , linux-kernel , "intel-gfx@lists.freedesktop.org" , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , linux-arm-kernel , "linuxppc-dev@lists.ozlabs.org" , "linux-parisc@vger.kernel.org" , oprofile-list@lists.sf.net, "linux-doc@vger.kernel.org" , linux-man@vger.kernel.org References: Organization: Intel Corp. Message-ID: <3364fa26-b5d1-1808-aaee-c057f26e0eb4@linux.intel.com> Date: Mon, 17 Feb 2020 11:07:37 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@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 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 46464367c47a..4564caa2c527 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9107,7 +9107,7 @@ 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; /* @@ -9167,7 +9167,7 @@ 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; /*