From patchwork Wed Feb 5 17:30:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Budankov X-Patchwork-Id: 11366739 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 AB9B7921 for ; Wed, 5 Feb 2020 17:31:09 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 89D1B217F4 for ; Wed, 5 Feb 2020 17:31:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AT4boxL2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89D1B217F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:References:To:From:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=JGi08jb1oILU8wa8ojU0Ebmx/12XOwbbGghSQLYM/2U=; b=AT4boxL2v0Npl6 o0ELEVcjMBekhd2r4rRB0xkxYobWArA2NY2J2WpuFx/Y9U4iu1EP8vd78VX07lcsj8pPSSiaIp/mQ orXwhRPeKApGjZhgjQCPfYDLGeC3DfNQQtlq6MqRRP+J4IZ/bHoYltdcE9goyDe9ou8op+9UKfUm/ JQ/qAW5Cv/wNPQBYT1iVfYQGHlvtO4ZYvVRmxPfhr7lH3ARRqcH1AdMwGQWgpIw1hY3kRB+7qJJkC nsNnhpDBR77zunNwGzM/9xF6BJS+/MWycZYCb3RLWfJFJiK/LW+yJWbnbbQHQzYusq4gi5u33XKcO DvVzZa009Aw/HbHpnSpA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1izOW4-0002Lt-1Q; Wed, 05 Feb 2020 17:31:08 +0000 Received: from mga14.intel.com ([192.55.52.115]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1izOW1-0002L2-Fe for linux-arm-kernel@lists.infradead.org; Wed, 05 Feb 2020 17:31:06 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2020 09:31:03 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,406,1574150400"; d="scan'208";a="343791237" Received: from linux.intel.com ([10.54.29.200]) by fmsmga001.fm.intel.com with ESMTP; 05 Feb 2020 09:31:03 -0800 Received: from [10.252.5.149] (abudanko-mobl.ccr.corp.intel.com [10.252.5.149]) by linux.intel.com (Postfix) with ESMTP id 863EC5803E3; Wed, 5 Feb 2020 09:30:56 -0800 (PST) Subject: [PATCH v6 02/10] perf/core: open access to the core 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 , Michael Ellerman References: <576a6141-36d4-14c0-b395-8d195892b916@linux.intel.com> Organization: Intel Corp. Message-ID: <0f35b211-b719-3c91-e067-2c63560c5af8@linux.intel.com> Date: Wed, 5 Feb 2020 20:30:55 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <576a6141-36d4-14c0-b395-8d195892b916@linux.intel.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200205_093105_548601_C67B7AB0 X-CRM114-Status: GOOD ( 16.56 ) X-Spam-Score: -5.0 (-----) X-Spam-Report: SpamAssassin version 3.4.3 on bombadil.infradead.org summary: Content analysis details: (-5.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [192.55.52.115 listed in list.dnswl.org] 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andi Kleen , "linux-parisc@vger.kernel.org" , "selinux@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "intel-gfx@lists.freedesktop.org" , Igor Lubashev , linux-kernel , Stephane Eranian , "linux-security-module@vger.kernel.org" , oprofile-list@lists.sf.net, Thomas Gleixner , Jiri Olsa , linux-arm-kernel Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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; }