From patchwork Mon Jan 20 11:23:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Budankov X-Patchwork-Id: 11341767 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 BCF8413BD for ; Mon, 20 Jan 2020 11:23:23 +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 9AFBF20882 for ; Mon, 20 Jan 2020 11:23:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="hqUJghMP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9AFBF20882 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=hVkLwt0A0FTdFLkeUGTk1Nfzh75pbPGQw3Os9cEJI7c=; b=hqUJghMPKrkg5B S0JvlGjysPeINw/zgxX02+C1uwR6MeUSLxJkktRA8hbn4CnwP7QtiKcEVQVw51SPMcYZg38OuWSUY WmMFLcpQEzfsh+K8O4mizFAzm3NHWP4l8/5iR0yfu8gxyN2q0OMAEAvTbmdQtEX2KrIzpd7Bnc3an mUVAMnHKeGhMWaWWwf+L8uPY5FuYftmuLOEzyWFaLh4TrBc7feNJ0w2dqWe1tUU4ZKwAl24R8JY3u YrhkgQx26aKMsknbbNusYkkMTFzvk9kWZDgcAYo7XLupAU8jiq3Wy3Xhcp9NHe7wyOlrwFa72inJ0 /6a+H3vZqKWE0NnNEuAQ==; 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 1itV9M-0001AL-Nv; Mon, 20 Jan 2020 11:23:20 +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 1itV9F-00019F-TV for linux-arm-kernel@lists.infradead.org; Mon, 20 Jan 2020 11:23:18 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jan 2020 03:23:11 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,341,1574150400"; d="scan'208";a="244380297" Received: from linux.intel.com ([10.54.29.200]) by orsmga002.jf.intel.com with ESMTP; 20 Jan 2020 03:23:10 -0800 Received: from [10.125.252.193] (abudanko-mobl.ccr.corp.intel.com [10.125.252.193]) by linux.intel.com (Postfix) with ESMTP id 386365802C1; Mon, 20 Jan 2020 03:23:01 -0800 (PST) Subject: [PATCH v5 01/10] capabilities: introduce CAP_PERFMON to kernel and user space From: Alexey Budankov To: Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "jani.nikula@linux.intel.com" , "joonas.lahtinen@linux.intel.com" , "rodrigo.vivi@intel.com" , "benh@kernel.crashing.org" , Paul Mackerras , Michael Ellerman , "james.bottomley@hansenpartnership.com" , Serge Hallyn , James Morris , Will Deacon , Mark Rutland , Robert Richter , Alexei Starovoitov References: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com> Organization: Intel Corp. Message-ID: <9b77124b-675d-5ac7-3741-edec575bd425@linux.intel.com> Date: Mon, 20 Jan 2020 14:23:00 +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: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200120_032313_963005_5B3F6E52 X-CRM114-Status: GOOD ( 16.48 ) 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: Song Liu , Andi Kleen , "linux-parisc@vger.kernel.org" , Alexander Shishkin , "linuxppc-dev@lists.ozlabs.org" , "intel-gfx@lists.freedesktop.org" , Igor Lubashev , linux-kernel , Stephane Eranian , "linux-perf-users@vger.kernel.org" , "selinux@vger.kernel.org" , "linux-security-module@vger.kernel.org" , oprofile-list@lists.sf.net, Lionel Landwerlin , Namhyung Kim , Thomas Gleixner , Jiri Olsa , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Introduce CAP_PERFMON capability designed to secure system performance monitoring and observability operations so that CAP_PERFMON would assist CAP_SYS_ADMIN capability in its governing role for perf_events, i915_perf and other performance monitoring and observability subsystems. CAP_PERFMON intends to harden system security and integrity during system performance monitoring and observability operations by decreasing attack surface that is available to a CAP_SYS_ADMIN privileged process [1]. Providing access to system performance monitoring and observability operations 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 intends to take over CAP_SYS_ADMIN credentials related to system performance monitoring and observability operations and balance amount of CAP_SYS_ADMIN credentials following the recommendations in the capabilities man page [1] for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel developers, below." Although the software running under CAP_PERFMON can not ensure avoidance of related hardware issues, the software can still mitigate these issues following the official embargoed hardware issues mitigation procedure [2]. The bugs in the software itself could be fixed following the standard kernel development process [3] to maintain and harden security of system performance monitoring and observability operations. [1] http://man7.org/linux/man-pages/man7/capabilities.7.html [2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html [3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html Signed-off-by: Alexey Budankov --- include/linux/capability.h | 12 ++++++++++++ include/uapi/linux/capability.h | 8 +++++++- security/selinux/include/classmap.h | 4 ++-- 3 files changed, 21 insertions(+), 3 deletions(-) diff --git a/include/linux/capability.h b/include/linux/capability.h index ecce0f43c73a..8784969d91e1 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -251,6 +251,18 @@ extern bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap); extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns); +static inline bool perfmon_capable(void) +{ + struct user_namespace *ns = &init_user_ns; + + if (ns_capable_noaudit(ns, CAP_PERFMON)) + return ns_capable(ns, CAP_PERFMON); + + if (ns_capable_noaudit(ns, CAP_SYS_ADMIN)) + return ns_capable(ns, CAP_SYS_ADMIN); + + return false; +} /* audit system wants to get cap info from files as well */ extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 240fdb9a60f6..8b416e5f3afa 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -366,8 +366,14 @@ struct vfs_ns_cap_data { #define CAP_AUDIT_READ 37 +/* + * Allow system performance and observability privileged operations + * using perf_events, i915_perf and other kernel subsystems + */ + +#define CAP_PERFMON 38 -#define CAP_LAST_CAP CAP_AUDIT_READ +#define CAP_LAST_CAP CAP_PERFMON #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index 7db24855e12d..c599b0c2b0e7 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -27,9 +27,9 @@ "audit_control", "setfcap" #define COMMON_CAP2_PERMS "mac_override", "mac_admin", "syslog", \ - "wake_alarm", "block_suspend", "audit_read" + "wake_alarm", "block_suspend", "audit_read", "perfmon" -#if CAP_LAST_CAP > CAP_AUDIT_READ +#if CAP_LAST_CAP > CAP_PERFMON #error New capability defined, please update COMMON_CAP2_PERMS. #endif