From patchwork Mon Apr 20 11:52:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498703 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 C526E13B2 for ; Mon, 20 Apr 2020 11:53:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A825620724 for ; Mon, 20 Apr 2020 11:53:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383630; bh=bsha3xY0b0htxjAC74+rhyzPRn3pa6BRck29iTQylnQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dgGS72MqI3XkhFrlH6AH6YTZ5YqfLY53otrxvW0km1ZKmCFDWRXFjGCOR1n5bUz5X pBZf1CrpNTIO+2pUuMNzUhQ5rlwDRw1kwcwdTKrSx8WI+51MFtwd0jAAa8amgu3uxG ITqh652/f1RKSMY3aoupbcDTVVntDyC1SeZRQP70= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726575AbgDTLxt (ORCPT ); Mon, 20 Apr 2020 07:53:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:37044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLxt (ORCPT ); Mon, 20 Apr 2020 07:53:49 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 310DA2223D; Mon, 20 Apr 2020 11:53:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383628; bh=bsha3xY0b0htxjAC74+rhyzPRn3pa6BRck29iTQylnQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=phe5YIfAUSL+rC4oWdSjzR1wUGQeb+JO0mjIAlFKvoq2kzj3RlwuD1fKv8mQogW4y +doqKnCO6GGPJakj9XBL13XfK7Gyfr1ef+W5b7V0D7a4ywOc3bMGUSYNMd7doIuJas KZSMookixBtF0laYrWAn6GknQWOCTrtIHGPG1pl0= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , "Serge E . Hallyn" , Song Liu , Stephen Smalley , Arnaldo Carvalho de Melo , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Subject: [PATCH 05/60] capabilities: Introduce CAP_PERFMON to kernel and user space Date: Mon, 20 Apr 2020 08:52:21 -0300 Message-Id: <20200420115316.18781-6-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Introduce the CAP_PERFMON capability designed to secure system performance monitoring and observability operations so that CAP_PERFMON can assist CAP_SYS_ADMIN capability in its governing role for performance monitoring and observability subsystems. CAP_PERFMON hardens system security and integrity during performance monitoring and observability operations by decreasing attack surface that is available to a CAP_SYS_ADMIN privileged process [2]. Providing the 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 the operation more secure. Thus, CAP_PERFMON implements the principle 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) CAP_PERFMON meets the demand to secure system performance monitoring and observability operations for adoption in security sensitive, restricted, multiuser production environments (e.g. HPC clusters, cloud and virtual compute environments), where root or CAP_SYS_ADMIN credentials are not available to mass users of a system, and securely unblocks applicability and scalability of system performance monitoring and observability operations beyond root and CAP_SYS_ADMIN use cases. CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance monitoring and observability operations and balances 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." For backward compatibility reasons access to system performance monitoring and observability subsystems of the kernel remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability usage for secure system performance monitoring and observability operations is discouraged with respect to the designed CAP_PERFMON capability. 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 hardware issues mitigation procedure [2]. The bugs in the software itself can 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 Acked-by: James Morris Acked-by: Serge E. Hallyn Acked-by: Song Liu Acked-by: Stephen Smalley Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/5590d543-82c6-490a-6544-08e6a5517db0@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- include/linux/capability.h | 4 ++++ include/uapi/linux/capability.h | 8 +++++++- security/selinux/include/classmap.h | 4 ++-- 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/include/linux/capability.h b/include/linux/capability.h index ecce0f43c73a..027d7e4a853b 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -251,6 +251,10 @@ 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) +{ + return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN); +} /* 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 272dc69fa080..e58c9636741b 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -367,8 +367,14 @@ 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 986f3ac14282..d233ab3f1533 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 From patchwork Mon Apr 20 11:52:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498707 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 329FB913 for ; Mon, 20 Apr 2020 11:53:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B9AB218AC for ; Mon, 20 Apr 2020 11:53:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383636; bh=PWjy/B+21HQPLawk/uU7/6+PxUTYrdc8ItS1u38jg7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0tznH8R4l/Zx1oN7TLQvvdwvUHA9h+ta0W11CDTKrFbWJh/rtcX8UwnmV8N+eEuxo jYlwSXjDgKA4FXQ0KrEjzR/Mvq7ObX8vQJKod/ea9OmppuXLrondSV+kBiDi6nnENk WU2u9zFXpj5y5/7O8WIdgm8xycD7WiIQrAyBBWJY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726615AbgDTLxz (ORCPT ); Mon, 20 Apr 2020 07:53:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:37208 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLxy (ORCPT ); Mon, 20 Apr 2020 07:53:54 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EE2F3206D4; Mon, 20 Apr 2020 11:53:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383634; bh=PWjy/B+21HQPLawk/uU7/6+PxUTYrdc8ItS1u38jg7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CrCekbuQzUEiHVCs3rvwQlRQOhBIgD9Yfij35aayQghq4Xtruet5C9dhhuUzK2CZ+ d3YqNFRVpyou2eNrp2a0PY1TfH0jRdom/Gyv95KZ7+O+sTqBVmuMoifnhQAwhz/O6I +thbwzrPtr5UJVdSyP4QNQlXSsrKp0pn1W1d7T0o= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Arnaldo Carvalho de Melo , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , linux-man@vger.kernel.org, Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Subject: [PATCH 06/60] perf/core: Open access to the core for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:22 -0300 Message-Id: <20200420115316.18781-7-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov 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 principle 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 the 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 Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: linux-man@vger.kernel.org Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/471acaef-bb8a-5ce2-923f-90606b78eef9@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 9c3e7619c929..87e21681759c 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1305,7 +1305,7 @@ 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); @@ -1313,7 +1313,7 @@ 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); @@ -1321,7 +1321,7 @@ 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 bc9b98a9af9a..74025b7b83a0 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11504,7 +11504,7 @@ SYSCALL_DEFINE5(perf_event_open, } if (attr.namespaces) { - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; } From patchwork Mon Apr 20 11:52:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498711 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 9B48913B2 for ; Mon, 20 Apr 2020 11:54:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8330B218AC for ; Mon, 20 Apr 2020 11:54:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383641; bh=+xEoiGPexvXw2sKFmZsWTCkSb2u7zsmlJFePteV0FYE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AKwgw9Mnkwdua5C9nsZPaaBiw0juxvRpOa6VBWfdwvGuJz1+m/RJ6CJz5ZvlXUvFt E6bjQL5we7V1NxlvgrueDDdd9kDhr8bt+sKlxoYj9hYO+EsDmHjZDP/Fc1BCQpG44Y cNITBSqdEGJoyjJYjpmugRLrxMbQGWFAI44NziNI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726654AbgDTLyA (ORCPT ); Mon, 20 Apr 2020 07:54:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:37386 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLyA (ORCPT ); Mon, 20 Apr 2020 07:54:00 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 87015214AF; Mon, 20 Apr 2020 11:53:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383639; bh=+xEoiGPexvXw2sKFmZsWTCkSb2u7zsmlJFePteV0FYE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cuxBGSfRM4mRwroR4FIXEnNSGjpXChR/18QORf1aWO5Ws3tHERNUr2V8I9rGMPfTV 9Qg0223aE3K1su8NJ0dtffFB+M/XgJ4IJPHFvutrKex5xDUZOQ9S4Ed61HkCr7WdfY OrYbuTChIvtETvHspP58GF4PXceYL9cN2mv2ihrY= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Arnaldo Carvalho de Melo , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, linux-man@vger.kernel.org Subject: [PATCH 07/60] perf/core: open access to probes for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:23 -0300 Message-Id: <20200420115316.18781-8-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov 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 principle 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 Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Cc: linux-man@vger.kernel.org Link: http://lore.kernel.org/lkml/3c129d9a-ba8a-3483-ecc5-ad6c8e7c203f@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 74025b7b83a0..52951e9e8e1b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9397,7 +9397,7 @@ 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; /* @@ -9457,7 +9457,7 @@ 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; /* From patchwork Mon Apr 20 11:52:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498717 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 0DB5713B2 for ; Mon, 20 Apr 2020 11:54:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E6226218AC for ; Mon, 20 Apr 2020 11:54:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383652; bh=umG+YWaiExRXDnhNmpqcQ9lrrT+f4USJnNtIo1+UQgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gtaXdYcFOqqovIdosz4TKFTbj7/UbrqXDCISkOX941FvCiWJmEGEue3+9gSZau8Xn Qhy6XWdjiDGhI27qZFo1FPSle/NxA4yk2hamt9W9M6SqMjT9aAIUEoD4UnUFoV4v8x DSU+jnH9sSDAImEg8XhRR5B3YzSDMshqal1dqR5M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726420AbgDTLyI (ORCPT ); Mon, 20 Apr 2020 07:54:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:37572 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLyH (ORCPT ); Mon, 20 Apr 2020 07:54:07 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1D525221F4; Mon, 20 Apr 2020 11:53:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383645; bh=umG+YWaiExRXDnhNmpqcQ9lrrT+f4USJnNtIo1+UQgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WXBIjllUt77fRSm6WW7EQl2ahuQBeHlt0BWzowwNO31l6OIrPh4aRriHVnxSk9Dpr HqzsrCzK2lGK/USKttN4Ma9dnN7tUxcFoszzIm/MrC4VhXoGSm26MTqHPBe/jD7gEL qvObofntHnBNrRImPy/eGPdC8Fcv+6wh2NlAWdjw= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Jiri Olsa , Arnaldo Carvalho de Melo , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Subject: [PATCH 08/60] perf tools: Support CAP_PERFMON capability Date: Mon, 20 Apr 2020 08:52:24 -0300 Message-Id: <20200420115316.18781-9-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Extend error messages to mention CAP_PERFMON capability as an option to substitute CAP_SYS_ADMIN capability for secure system performance monitoring and observability operations. Make perf_event_paranoid_check() and __cmd_ftrace() to be aware of CAP_PERFMON capability. CAP_PERFMON implements the principle 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. Committer testing: Using a libcap with this patch: diff --git a/libcap/include/uapi/linux/capability.h b/libcap/include/uapi/linux/capability.h index 78b2fd4c8a95..89b5b0279b60 100644 --- a/libcap/include/uapi/linux/capability.h +++ b/libcap/include/uapi/linux/capability.h @@ -366,8 +366,9 @@ struct vfs_ns_cap_data { #define CAP_AUDIT_READ 37 +#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) Note that using '38' in place of 'cap_perfmon' works to some degree with an old libcap, its only when cap_get_flag() is called that libcap performs an error check based on the maximum value known for capabilities that it will fail. This makes determining the default of perf_event_attr.exclude_kernel to fail, as it can't determine if CAP_PERFMON is in place. Using 'perf top -e cycles' avoids the default check and sets perf_event_attr.exclude_kernel to 1. As root, with a libcap supporting CAP_PERFMON: # groupadd perf_users # adduser perf -g perf_users # mkdir ~perf/bin # cp ~acme/bin/perf ~perf/bin/ # chgrp perf_users ~perf/bin/perf # setcap "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" ~perf/bin/perf # getcap ~perf/bin/perf /home/perf/bin/perf = cap_sys_ptrace,cap_syslog,cap_perfmon+ep # ls -la ~perf/bin/perf -rwxr-xr-x. 1 root perf_users 16968552 Apr 9 13:10 /home/perf/bin/perf As the 'perf' user in the 'perf_users' group: $ perf top -a --stdio Error: Failed to mmap with 1 (Operation not permitted) $ Either add the cap_ipc_lock capability to the perf binary or reduce the ring buffer size to some smaller value: $ perf top -m10 -a --stdio rounding mmap pages size to 64K (16 pages) Error: Failed to mmap with 1 (Operation not permitted) $ perf top -m4 -a --stdio Error: Failed to mmap with 1 (Operation not permitted) $ perf top -m2 -a --stdio PerfTop: 762 irqs/sec kernel:49.7% exact: 100.0% lost: 0/0 drop: 0/0 [4000Hz cycles], (all, 4 CPUs) ------------------------------------------------------------------------------------------------------ 9.83% perf [.] __symbols__insert 8.58% perf [.] rb_next 5.91% [kernel] [k] module_get_kallsym 5.66% [kernel] [k] kallsyms_expand_symbol.constprop.0 3.98% libc-2.29.so [.] __GI_____strtoull_l_internal 3.66% perf [.] rb_insert_color 2.34% [kernel] [k] vsnprintf 2.30% [kernel] [k] string_nocheck 2.16% libc-2.29.so [.] _IO_getdelim 2.15% [kernel] [k] number 2.13% [kernel] [k] format_decode 1.58% libc-2.29.so [.] _IO_feof 1.52% libc-2.29.so [.] __strcmp_avx2 1.50% perf [.] rb_set_parent_color 1.47% libc-2.29.so [.] __libc_calloc 1.24% [kernel] [k] do_syscall_64 1.17% [kernel] [k] __x86_indirect_thunk_rax $ perf record -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.552 MB perf.data (74 samples) ] $ perf evlist cycles $ perf evlist -v cycles: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1 $ perf report | head -20 # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 74 of event 'cycles' # Event count (approx.): 15694834 # # Overhead Command Shared Object Symbol # ........ ............... .......................... ...................................... # 19.62% perf [kernel.vmlinux] [k] strnlen_user 13.88% swapper [kernel.vmlinux] [k] intel_idle 13.83% ksoftirqd/0 [kernel.vmlinux] [k] pfifo_fast_dequeue 13.51% swapper [kernel.vmlinux] [k] kmem_cache_free 6.31% gnome-shell [kernel.vmlinux] [k] kmem_cache_free 5.66% kworker/u8:3+ix [kernel.vmlinux] [k] delay_tsc 4.42% perf [kernel.vmlinux] [k] __set_cpus_allowed_ptr 3.45% kworker/2:1-eve [kernel.vmlinux] [k] shmem_truncate_range 2.29% gnome-shell libgobject-2.0.so.0.6000.7 [.] g_closure_ref $ Signed-off-by: Alexey Budankov Reviewed-by: James Morris Acked-by: Jiri Olsa Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/a66d5648-2b8e-577e-e1f2-1d56c017ab5e@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-ftrace.c | 5 +++-- tools/perf/design.txt | 3 ++- tools/perf/util/cap.h | 4 ++++ tools/perf/util/evsel.c | 10 +++++----- tools/perf/util/util.c | 1 + 5 files changed, 15 insertions(+), 8 deletions(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index d5adc417a4ca..55eda54240fb 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -284,10 +284,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) .events = POLLIN, }; - if (!perf_cap__capable(CAP_SYS_ADMIN)) { + if (!(perf_cap__capable(CAP_PERFMON) || + perf_cap__capable(CAP_SYS_ADMIN))) { pr_err("ftrace only works for %s!\n", #ifdef HAVE_LIBCAP_SUPPORT - "users with the SYS_ADMIN capability" + "users with the CAP_PERFMON or CAP_SYS_ADMIN capability" #else "root" #endif diff --git a/tools/perf/design.txt b/tools/perf/design.txt index 0453ba26cdbd..a42fab308ff6 100644 --- a/tools/perf/design.txt +++ b/tools/perf/design.txt @@ -258,7 +258,8 @@ gets schedule to. Per task counters can be created by any user, for their own tasks. A 'pid == -1' and 'cpu == x' counter is a per CPU counter that counts -all events on CPU-x. Per CPU counters need CAP_SYS_ADMIN privilege. +all events on CPU-x. Per CPU counters need CAP_PERFMON or CAP_SYS_ADMIN +privilege. The 'flags' parameter is currently unused and must be zero. diff --git a/tools/perf/util/cap.h b/tools/perf/util/cap.h index 051dc590ceee..ae52878c0b2e 100644 --- a/tools/perf/util/cap.h +++ b/tools/perf/util/cap.h @@ -29,4 +29,8 @@ static inline bool perf_cap__capable(int cap __maybe_unused) #define CAP_SYSLOG 34 #endif +#ifndef CAP_PERFMON +#define CAP_PERFMON 38 +#endif + #endif /* __PERF_CAP_H */ diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index eb880efbce16..d23db6755f51 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2523,14 +2523,14 @@ int perf_evsel__open_strerror(struct evsel *evsel, struct target *target, "You may not have permission to collect %sstats.\n\n" "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n" "which controls use of the performance events system by\n" - "unprivileged users (without CAP_SYS_ADMIN).\n\n" + "unprivileged users (without CAP_PERFMON or CAP_SYS_ADMIN).\n\n" "The current value is %d:\n\n" " -1: Allow use of (almost) all events by all users\n" " Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n" - ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n" - " Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n" - ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n" - ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n" + ">= 0: Disallow ftrace function tracepoint by users without CAP_PERFMON or CAP_SYS_ADMIN\n" + " Disallow raw tracepoint access by users without CAP_SYS_PERFMON or CAP_SYS_ADMIN\n" + ">= 1: Disallow CPU event access by users without CAP_PERFMON or CAP_SYS_ADMIN\n" + ">= 2: Disallow kernel profiling by users without CAP_PERFMON or CAP_SYS_ADMIN\n\n" "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n" " kernel.perf_event_paranoid = -1\n" , target->system_wide ? "system-wide " : "", diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index d707c9624dd9..37a9492edb3e 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -290,6 +290,7 @@ int perf_event_paranoid(void) bool perf_event_paranoid_check(int max_level) { return perf_cap__capable(CAP_SYS_ADMIN) || + perf_cap__capable(CAP_PERFMON) || perf_event_paranoid() <= max_level; } From patchwork Mon Apr 20 11:52:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498725 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 8B0CF13B2 for ; Mon, 20 Apr 2020 11:54:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 740AC21927 for ; Mon, 20 Apr 2020 11:54:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383663; bh=KcU35D57021g0uqwoqjTd5rmvJznq2uTIrvtUOTNjoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QXhEeimRcio1Vbxg3SPmQirmK2jKoodv8pCUcn1oXXriuYWvPk2166iJh7uhHI6+x QTaAiFziwRJa08XA7iPSjocDwPZwcomXOxMkEg4dJzayu8gf8vUfXBjiTrvjisKYJW dfXgndfZJhPNGfw8+njGe9/PPdwP8v55VZIVPZBU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726702AbgDTLyP (ORCPT ); Mon, 20 Apr 2020 07:54:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:37718 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLyL (ORCPT ); Mon, 20 Apr 2020 07:54:11 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A42EA206D4; Mon, 20 Apr 2020 11:54:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383651; bh=KcU35D57021g0uqwoqjTd5rmvJznq2uTIrvtUOTNjoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rNdaTZCIqUpvS2/vtJgLe1A/O/b62vWFcdSB0uWWp514bDGzm+/OnU23mIyftpmFn c2KI+6Qr0SEbpUkGpBtgl8oH4TunkeFPTGDCnWwHuO5DQlrpqfVJ9hQXTCeAAY/KAG 3+kQQupT+ZflY0kILRangxmd174cJvhZC+CKjCGg= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Lionel Landwerlin , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Arnaldo Carvalho de Melo Subject: [PATCH 09/60] drm/i915/perf: Open access for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:25 -0300 Message-Id: <20200420115316.18781-10-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Open access to i915_perf monitoring 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. CAP_PERFMON implements the principle 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 i915_events subsystem remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure i915_events monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov Reviewed-by: James Morris Acked-by: Lionel Landwerlin Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/e3e3292f-f765-ea98-e59c-fbe2db93fd34@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- drivers/gpu/drm/i915/i915_perf.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 551be589d6f4..5fb174931231 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -3433,10 +3433,10 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf, /* Similar to perf's kernel.perf_paranoid_cpu sysctl option * we check a dev.i915.perf_stream_paranoid sysctl option * to determine if it's ok to access system wide OA counters - * without CAP_SYS_ADMIN privileges. + * without CAP_PERFMON or CAP_SYS_ADMIN privileges. */ if (privileged_op && - i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { + i915_perf_stream_paranoid && !perfmon_capable()) { DRM_DEBUG("Insufficient privileges to open i915 perf stream\n"); ret = -EACCES; goto err_ctx; @@ -3629,9 +3629,8 @@ static int read_properties_unlocked(struct i915_perf *perf, } else oa_freq_hz = 0; - if (oa_freq_hz > i915_oa_max_sample_rate && - !capable(CAP_SYS_ADMIN)) { - DRM_DEBUG("OA exponent would exceed the max sampling frequency (sysctl dev.i915.oa_max_sample_rate) %uHz without root privileges\n", + if (oa_freq_hz > i915_oa_max_sample_rate && !perfmon_capable()) { + DRM_DEBUG("OA exponent would exceed the max sampling frequency (sysctl dev.i915.oa_max_sample_rate) %uHz without CAP_PERFMON or CAP_SYS_ADMIN privileges\n", i915_oa_max_sample_rate); return -EACCES; } @@ -4052,7 +4051,7 @@ int i915_perf_add_config_ioctl(struct drm_device *dev, void *data, return -EINVAL; } - if (i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { + if (i915_perf_stream_paranoid && !perfmon_capable()) { DRM_DEBUG("Insufficient privileges to add i915 OA config\n"); return -EACCES; } @@ -4199,7 +4198,7 @@ int i915_perf_remove_config_ioctl(struct drm_device *dev, void *data, return -ENOTSUPP; } - if (i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { + if (i915_perf_stream_paranoid && !perfmon_capable()) { DRM_DEBUG("Insufficient privileges to remove i915 OA config\n"); return -EACCES; } From patchwork Mon Apr 20 11:52:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498723 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 952B41667 for ; Mon, 20 Apr 2020 11:54:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D33922242 for ; Mon, 20 Apr 2020 11:54:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383662; bh=iEHcbd3dsEh+nbBrF8hA7DMxqrfUdFplqLITI+edP6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oSDv4ZqshYNqWSoRzGFh7Wy9ExED83+cqYxo8HvBjXccOqak4EEFCsb8Xxv+x8NvS TK4h9qN25TiJK2y3OaQgQJSs7rz1kYl4iEwzy8alpd+RzH6Q2xnvkfZpq1cq+pBUf+ 9STlqgqYcqd3AFUFJS1+NZxwPj6Wz04qyptv2q/I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726723AbgDTLyS (ORCPT ); Mon, 20 Apr 2020 07:54:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:37862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLyR (ORCPT ); Mon, 20 Apr 2020 07:54:17 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 72CBD2223D; Mon, 20 Apr 2020 11:54:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383656; bh=iEHcbd3dsEh+nbBrF8hA7DMxqrfUdFplqLITI+edP6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1kGbFMlV8el+e/SiyC20aoUKm7KCmmcWzC0NCYLBNYBAb+FnkpxtWCYse/Xqrtsu6 2NDEg5qs/wtl0DWBL7RDY4YF23woE7ziJLEoSVANBnqvAAE3otm6HOPS5pgeT31L2l 6lda91V/cLs5kDaC9Dp8mfjaXG3WDy2R6MwTXWgI= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Song Liu , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Arnaldo Carvalho de Melo Subject: [PATCH 10/60] trace/bpf_trace: Open access for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:26 -0300 Message-Id: <20200420115316.18781-11-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Open access to bpf_trace monitoring 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. CAP_PERFMON implements the principle 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 bpf_trace monitoring remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure bpf_trace monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov Reviewed-by: James Morris Acked-by: Song Liu Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/c0a0ae47-8b6e-ff3e-416b-3cd1faaf71c0@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- kernel/trace/bpf_trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index ca1796747a77..d7d88007dc6d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1468,7 +1468,7 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info) u32 *ids, prog_cnt, ids_len; int ret; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EPERM; if (event->attr.type != PERF_TYPE_TRACEPOINT) return -EINVAL; From patchwork Mon Apr 20 11:52:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498727 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 4B57B913 for ; Mon, 20 Apr 2020 11:54:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 351D1214AF for ; Mon, 20 Apr 2020 11:54:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383665; bh=BOa5Mw0/hpw+98z21+6ed6jZc+vUnN9uwr6UPY2Ps1g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AjeJzjpzJSu1oL5QDSNe0zdkuYBPt27TcXuz4aOlEbCGRa2uRfMwIHsGfhEnsNRVc 4ztD/yrM9umWb86lvwA/802Vg31zEeGoL9nXRgPIsFOpYE0bPU1csU8d95s7vSY7En gq4wP5m6gvq6UlAqAnSWiJ18iv+/lwUHpSLCrPzU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726748AbgDTLyY (ORCPT ); Mon, 20 Apr 2020 07:54:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:38068 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLyX (ORCPT ); Mon, 20 Apr 2020 07:54:23 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0969C21D94; Mon, 20 Apr 2020 11:54:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383662; bh=BOa5Mw0/hpw+98z21+6ed6jZc+vUnN9uwr6UPY2Ps1g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VXwto54smORPjo0Ke2LCHi8I/iZHqIoqAIdoHvug3M0BQDLEWe1njfHDGO98wHT+A eIwqkCs5YR8BVWAyu9kGhiVBI6Sys36FvQE0MuLfs+vEUWVECE7Gt8b5MN+EAeLO57 FBgxuPhdNbgEHCzbXSUh9vCwk2eU8ljKMe0c1otI= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Anju T Sudhakar , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Arnaldo Carvalho de Melo Subject: [PATCH 11/60] powerpc/perf: open access for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:27 -0300 Message-Id: <20200420115316.18781-12-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Open access to monitoring 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. CAP_PERFMON implements the principle 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 the monitoring remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov Reviewed-by: James Morris Acked-by: Anju T Sudhakar Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/ac98cd9f-b59e-673c-c70d-180b3e7695d2@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- arch/powerpc/perf/imc-pmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c index eb82dda884e5..0edcfd0b491d 100644 --- a/arch/powerpc/perf/imc-pmu.c +++ b/arch/powerpc/perf/imc-pmu.c @@ -976,7 +976,7 @@ static int thread_imc_event_init(struct perf_event *event) if (event->attr.type != event->pmu->type) return -ENOENT; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; /* Sampling not supported */ @@ -1412,7 +1412,7 @@ static int trace_imc_event_init(struct perf_event *event) if (event->attr.type != event->pmu->type) return -ENOENT; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; /* Return if this is a couting event */ From patchwork Mon Apr 20 11:52:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498733 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 00660913 for ; Mon, 20 Apr 2020 11:54:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDD7D20724 for ; Mon, 20 Apr 2020 11:54:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383673; bh=PXwArPyrCB+9UYBajG3cuzXYyMjKBkArgtx7/t80yDQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=U3csoywjkGGXxsPYA/+32oa6kSeU1K0B53rKlu4B759xri9CnaROfG3XhtKdeErQl piF9GiEXQf6yqZDIRNgFKwFXQ+SHjFyIeeQKBbTzOo8tlUlsusj16q47ag5Rx05P3d VNQeK9DuUS+LMASyHsphKY5qM46/a603LmhE/Eys= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726758AbgDTLy3 (ORCPT ); Mon, 20 Apr 2020 07:54:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:38178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLy3 (ORCPT ); Mon, 20 Apr 2020 07:54:29 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C666822242; Mon, 20 Apr 2020 11:54:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383668; bh=PXwArPyrCB+9UYBajG3cuzXYyMjKBkArgtx7/t80yDQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jY2+DKBnaUefdix+56HKfjrYAILqIoOTLoPXsBbJO0L5LInIgkVs0qCZ8Yg/fPUK6 2tHiRgmIfuIa7QGLClBjTGyAcjdggANZIOwqayLKQ6rqbpLiUXfkfQ3IMnDnMB6VXV 4rvqseNET+8Y/H4ZEnP/LkycQBSNV+sn3xrHLOaI= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Helge Deller , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Arnaldo Carvalho de Melo Subject: [PATCH 12/60] parisc/perf: open access for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:28 -0300 Message-Id: <20200420115316.18781-13-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Open access to monitoring 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. CAP_PERFMON implements the principle 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 the monitoring remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov Reviewed-by: James Morris Acked-by: Helge Deller Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/8cc98809-d35b-de0f-de02-4cf554f3cf62@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- arch/parisc/kernel/perf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/parisc/kernel/perf.c b/arch/parisc/kernel/perf.c index e1a8fee3ad49..d46b6709ec56 100644 --- a/arch/parisc/kernel/perf.c +++ b/arch/parisc/kernel/perf.c @@ -300,7 +300,7 @@ static ssize_t perf_write(struct file *file, const char __user *buf, else return -EFAULT; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; if (count != sizeof(uint32_t)) From patchwork Mon Apr 20 11:52:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498737 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 4714A13B2 for ; Mon, 20 Apr 2020 11:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F6B320857 for ; Mon, 20 Apr 2020 11:54:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383679; bh=y2LqQNgk7M38l+vhlpVjFxZa1rdjNePBdEMgUzSLdhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=o3DfXifECX/pT7OzKpCG7QEWTEw7RM+RDui8Imj8gKE3LAkz8ZkGHBceNHeMvKIRA rFgzsZNPzGK2loWHdnjsJcwpk9vEtlR3FCuV1mYSt/t1NhC/6PA0JJKP18iU6vRV7t q+X9XMcagO0YHJ6SdN8FRFUK9OMwB+/q4WQkPmfo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726777AbgDTLyf (ORCPT ); Mon, 20 Apr 2020 07:54:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:38294 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLye (ORCPT ); Mon, 20 Apr 2020 07:54:34 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 91A9B22209; Mon, 20 Apr 2020 11:54:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383673; bh=y2LqQNgk7M38l+vhlpVjFxZa1rdjNePBdEMgUzSLdhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KmY2u1K51EPLK1W4HkWcxiMu51TD9ZSXYb13zKWfCWjai70Q8Mt9Cvt770iInsbtQ g8AVOWUObccLD/NwmWGV+gIdZkaAz7MecddQ4jlxq6zU+aw17sKhaDzzULzvSH/cZw ZDamnr+dVgOJGTQJ2HEZWdyGij56MK6jUwv5mAeg= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Will Deacon , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Arnaldo Carvalho de Melo Subject: [PATCH 13/60] drivers/perf: Open access for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:29 -0300 Message-Id: <20200420115316.18781-14-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Open access to monitoring 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. CAP_PERFMON implements the principle 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 the monitoring remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov Reviewed-by: James Morris Acked-by: Will Deacon Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/4ec1d6f7-548c-8d1c-f84a-cebeb9674e4e@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- drivers/perf/arm_spe_pmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c index b72c04852599..0e0961a2b405 100644 --- a/drivers/perf/arm_spe_pmu.c +++ b/drivers/perf/arm_spe_pmu.c @@ -274,7 +274,7 @@ static u64 arm_spe_event_to_pmscr(struct perf_event *event) if (!attr->exclude_kernel) reg |= BIT(SYS_PMSCR_EL1_E1SPE_SHIFT); - if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && capable(CAP_SYS_ADMIN)) + if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && perfmon_capable()) reg |= BIT(SYS_PMSCR_EL1_CX_SHIFT); return reg; @@ -700,7 +700,7 @@ static int arm_spe_pmu_event_init(struct perf_event *event) return -EOPNOTSUPP; reg = arm_spe_event_to_pmscr(event); - if (!capable(CAP_SYS_ADMIN) && + if (!perfmon_capable() && (reg & (BIT(SYS_PMSCR_EL1_PA_SHIFT) | BIT(SYS_PMSCR_EL1_CX_SHIFT) | BIT(SYS_PMSCR_EL1_PCT_SHIFT)))) From patchwork Mon Apr 20 11:52:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498741 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 AB45C913 for ; Mon, 20 Apr 2020 11:54:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 93F792072B for ; Mon, 20 Apr 2020 11:54:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383684; bh=9kpEN/lFo7jxjTeW9ri+Y7V19Ly0ojOP0oybPA/ulXo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JhUMUxqJy1TVQ5sNF1qGJEGVUd1QuvMjg96PCXgyiTa8eOyJAXHjlytYaaU+HuczM DrZ2qGtkSQgjXYUoSfcuOsM371E0QwLsQNIs0T6IGRgNtE0A2B21tRQapyMu8Ham0I XZxIhjmQQrKjmjIanAch2VoONb+Uu1gP8z7FdChk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726791AbgDTLyk (ORCPT ); Mon, 20 Apr 2020 07:54:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:38394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLyk (ORCPT ); Mon, 20 Apr 2020 07:54:40 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 618A52071C; Mon, 20 Apr 2020 11:54:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383679; bh=9kpEN/lFo7jxjTeW9ri+Y7V19Ly0ojOP0oybPA/ulXo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vdstaCdBEPjcbHiBf+qv7kBQk2d78WoaK9DBG7nXclPnVBZQIS/jSCIdibYMBXBdi /vapGFj285gW3uQF8x2sl38L2ryondYx0qsHDsNMEx3/TKkFc7XZOYTMp1eeBJ9Qtk o7R5EIAGKgLsZNmMQrQPxryhBN9ghIkxKJWPlS7U= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , James Morris , Alexei Starovoitov , Andi Kleen , Igor Lubashev , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Arnaldo Carvalho de Melo Subject: [PATCH 14/60] drivers/oprofile: Open access for CAP_PERFMON privileged process Date: Mon, 20 Apr 2020 08:52:30 -0300 Message-Id: <20200420115316.18781-15-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Open access to monitoring 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. CAP_PERFMON implements the principle 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 the monitoring remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov Acked-by: James Morris Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/691f1096-b15f-9b12-50a0-c2b93918149e@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- drivers/oprofile/event_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c index 12ea4a4ad607..6c9edc8bbc95 100644 --- a/drivers/oprofile/event_buffer.c +++ b/drivers/oprofile/event_buffer.c @@ -113,7 +113,7 @@ static int event_buffer_open(struct inode *inode, struct file *file) { int err = -EPERM; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EPERM; if (test_and_set_bit_lock(0, &buffer_opened)) From patchwork Mon Apr 20 11:52:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498743 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 BCBEB13B2 for ; Mon, 20 Apr 2020 11:54:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FA902072B for ; Mon, 20 Apr 2020 11:54:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383687; bh=svwfgxzDf5lHzQLtGzuG7pZIp4RfU3t8qP+aoqULD/c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LfsVqHyY8m8VuTEYPXdTPYDEK8gw7t9v5WiUPJKQgdobDsL2RHF4SB0q5QuL56Td+ azqXHdlNTgQDnxVUaQg5/CSPbiBDD7urHVNSTsIfFN5MtB+qMa8cBzx+nxnNpIjxhE Is8axIJbhR89dTG0y9SgVZdvbz5Mb4cexZ+XTS0Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726498AbgDTLyr (ORCPT ); Mon, 20 Apr 2020 07:54:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:38504 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbgDTLyq (ORCPT ); Mon, 20 Apr 2020 07:54:46 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EA3F820857; Mon, 20 Apr 2020 11:54:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383685; bh=svwfgxzDf5lHzQLtGzuG7pZIp4RfU3t8qP+aoqULD/c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pfF5W/f+AIIshpsrYdWaj7TwM4eC+WR38wEyS0e0GloJFBv7kAL3vQvdbenjSRfK4 +AnfHq0ElD0cxdfvkZUP9uqMQcP6D2k5bk05gXOd2S+4pt1Y7MWdhK3LSiTLQb8CKH Z+2DDh5Xl7Ya2iAZ3CNi+Fu9lQucv2Nn+GlCHpSc= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , Arnaldo Carvalho de Melo , Alexei Starovoitov , Andi Kleen , Igor Lubashev , James Morris , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Subject: [PATCH 15/60] doc/admin-guide: Update perf-security.rst with CAP_PERFMON information Date: Mon, 20 Apr 2020 08:52:31 -0300 Message-Id: <20200420115316.18781-16-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Update perf-security.rst documentation file with the information related to usage of CAP_PERFMON capability to secure performance monitoring and observability operations in system. Committer notes: While testing 'perf top' under cap_perfmon I noticed that it needs some more capability and Alexey pointed out cap_ipc_lock, as needed by this kernel chunk: kernel/events/core.c: 6101 if ((locked > lock_limit) && perf_is_paranoid() && !capable(CAP_IPC_LOCK)) { ret = -EPERM; goto unlock; } So I added it to the documentation, and also mentioned that if the libcap version doesn't yet supports 'cap_perfmon', its numeric value can be used instead, i.e. if: # setcap "cap_perfmon,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf Fails, try: # setcap "38,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf I also added a paragraph stating that using an unpatched libcap will fail the check for CAP_PERFMON, as it checks the cap number against a maximum to see if it is valid, which makes it use as the default the 'cycles:u' event, even tho a cap_perfmon capable perf binary can get kernel samples, to workaround that just use, e.g.: # perf top -e cycles # perf record -e cycles And it will sample kernel and user modes. Signed-off-by: Alexey Budankov Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: James Morris Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/17278551-9399-9ebe-d665-8827016a217d@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- Documentation/admin-guide/perf-security.rst | 86 +++++++++++++++------ 1 file changed, 61 insertions(+), 25 deletions(-) diff --git a/Documentation/admin-guide/perf-security.rst b/Documentation/admin-guide/perf-security.rst index 72effa7c23b9..1307b5274a0f 100644 --- a/Documentation/admin-guide/perf-security.rst +++ b/Documentation/admin-guide/perf-security.rst @@ -1,6 +1,6 @@ .. _perf_security: -Perf Events and tool security +Perf events and tool security ============================= Overview @@ -42,11 +42,11 @@ categories: Data that belong to the fourth category can potentially contain sensitive process data. If PMUs in some monitoring modes capture values of execution context registers or data from process memory then access -to such monitoring capabilities requires to be ordered and secured -properly. So, perf_events/Perf performance monitoring is the subject for -security access control management [5]_ . +to such monitoring modes requires to be ordered and secured properly. +So, perf_events performance monitoring and observability operations are +the subject for security access control management [5]_ . -perf_events/Perf access control +perf_events access control ------------------------------- To perform security checks, the Linux implementation splits processes @@ -66,11 +66,25 @@ into distinct units, known as capabilities [6]_ , which can be independently enabled and disabled on per-thread basis for processes and files of unprivileged users. -Unprivileged processes with enabled CAP_SYS_ADMIN capability are treated +Unprivileged processes with enabled CAP_PERFMON capability are treated as privileged processes with respect to perf_events performance -monitoring and bypass *scope* permissions checks in the kernel. - -Unprivileged processes using perf_events system call API is also subject +monitoring and observability operations, thus, bypass *scope* permissions +checks in the kernel. CAP_PERFMON implements the principle of least +privilege [13]_ (POSIX 1003.1e: 2.2.2.39) for performance monitoring and +observability operations in the kernel and provides a secure approach to +perfomance monitoring and observability in the system. + +For backward compatibility reasons the access to perf_events monitoring and +observability operations is also open for CAP_SYS_ADMIN privileged +processes but CAP_SYS_ADMIN usage for secure monitoring and observability +use cases is discouraged with respect to the CAP_PERFMON capability. +If system audit records [14]_ for a process using perf_events system call +API contain denial records of acquiring both CAP_PERFMON and CAP_SYS_ADMIN +capabilities then providing the process with CAP_PERFMON capability singly +is recommended as the preferred secure approach to resolve double access +denial logging related to usage of performance monitoring and observability. + +Unprivileged processes using perf_events system call are also subject for PTRACE_MODE_READ_REALCREDS ptrace access mode check [7]_ , whose outcome determines whether monitoring is permitted. So unprivileged processes provided with CAP_SYS_PTRACE capability are effectively @@ -82,14 +96,14 @@ performance analysis of monitored processes or a system. For example, CAP_SYSLOG capability permits reading kernel space memory addresses from /proc/kallsyms file. -perf_events/Perf privileged users +Privileged Perf users groups --------------------------------- Mechanisms of capabilities, privileged capability-dumb files [6]_ and -file system ACLs [10]_ can be used to create a dedicated group of -perf_events/Perf privileged users who are permitted to execute -performance monitoring without scope limits. The following steps can be -taken to create such a group of privileged Perf users. +file system ACLs [10]_ can be used to create dedicated groups of +privileged Perf users who are permitted to execute performance monitoring +and observability without scope limits. The following steps can be +taken to create such groups of privileged Perf users. 1. Create perf_users group of privileged Perf users, assign perf_users group to Perf tool executable and limit access to the executable for @@ -108,30 +122,51 @@ taken to create such a group of privileged Perf users. -rwxr-x--- 2 root perf_users 11M Oct 19 15:12 perf 2. Assign the required capabilities to the Perf tool executable file and - enable members of perf_users group with performance monitoring + enable members of perf_users group with monitoring and observability privileges [6]_ : :: - # setcap "cap_sys_admin,cap_sys_ptrace,cap_syslog=ep" perf - # setcap -v "cap_sys_admin,cap_sys_ptrace,cap_syslog=ep" perf + # setcap "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" perf + # setcap -v "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" perf perf: OK # getcap perf - perf = cap_sys_ptrace,cap_sys_admin,cap_syslog+ep + perf = cap_sys_ptrace,cap_syslog,cap_perfmon+ep + +If the libcap installed doesn't yet support "cap_perfmon", use "38" instead, +i.e.: + +:: + + # setcap "38,cap_ipc_lock,cap_sys_ptrace,cap_syslog=ep" perf + +Note that you may need to have 'cap_ipc_lock' in the mix for tools such as +'perf top', alternatively use 'perf top -m N', to reduce the memory that +it uses for the perf ring buffer, see the memory allocation section below. + +Using a libcap without support for CAP_PERFMON will make cap_get_flag(caps, 38, +CAP_EFFECTIVE, &val) fail, which will lead the default event to be 'cycles:u', +so as a workaround explicitly ask for the 'cycles' event, i.e.: + +:: + + # perf top -e cycles + +To get kernel and user samples with a perf binary with just CAP_PERFMON. As a result, members of perf_users group are capable of conducting -performance monitoring by using functionality of the configured Perf -tool executable that, when executes, passes perf_events subsystem scope -checks. +performance monitoring and observability by using functionality of the +configured Perf tool executable that, when executes, passes perf_events +subsystem scope checks. This specific access control management is only available to superuser or root running processes with CAP_SETPCAP, CAP_SETFCAP [6]_ capabilities. -perf_events/Perf unprivileged users +Unprivileged users ----------------------------------- -perf_events/Perf *scope* and *access* control for unprivileged processes +perf_events *scope* and *access* control for unprivileged processes is governed by perf_event_paranoid [2]_ setting: -1: @@ -166,7 +201,7 @@ is governed by perf_event_paranoid [2]_ setting: perf_event_mlock_kb locking limit is imposed but ignored for unprivileged processes with CAP_IPC_LOCK capability. -perf_events/Perf resource control +Resource control --------------------------------- Open file descriptors @@ -227,4 +262,5 @@ Bibliography .. [10] ``_ .. [11] ``_ .. [12] ``_ - +.. [13] ``_ +.. [14] ``_ From patchwork Mon Apr 20 11:52:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnaldo Carvalho de Melo X-Patchwork-Id: 11498747 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 149E313B2 for ; Mon, 20 Apr 2020 11:55:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F19E221927 for ; Mon, 20 Apr 2020 11:55:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383727; bh=VEov1HC8kgX2JVYBtf5NvQb82wHeJ2/NnuqpEyj7U+U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2eccO2jmHChu2uP5YxZGAHZvGOnah7NJo4w9gKENJ1zWuTrdTjn0B+8ydq662csWE NXrsXTulRjUewaqKku4D0j3+6pzniNonoZ2xBTXiYRA0D8tkAdl42FOLyJKJEFiL1n HBi6bIm09y045k9XT3HZEGZ5/p2Xx6LJVkhrH9Pk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726834AbgDTLyw (ORCPT ); Mon, 20 Apr 2020 07:54:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:38608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726821AbgDTLyv (ORCPT ); Mon, 20 Apr 2020 07:54:51 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8202A21927; Mon, 20 Apr 2020 11:54:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587383690; bh=VEov1HC8kgX2JVYBtf5NvQb82wHeJ2/NnuqpEyj7U+U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K2wA/sfFxecLv7R81Z3L8nQRfJzTKMqNt+FJN7nLvkxV66mZfO5u6jy9LnBfkf7ed 5jEJkZFGY7O11EbRbNmJ3pqEsYFpuOjmCkheRSJjCJxnsyW0RoFGzomKUWICd6Rzqx HE2UHsV3PClSWDXhumCf8dh4djMaGw2rLR076hRY= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexey Budankov , Alexei Starovoitov , Andi Kleen , Igor Lubashev , James Morris , Jiri Olsa , Peter Zijlstra , Serge Hallyn , Song Liu , Stephane Eranian , intel-gfx@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, Arnaldo Carvalho de Melo Subject: [PATCH 16/60] doc/admin-guide: update kernel.rst with CAP_PERFMON information Date: Mon, 20 Apr 2020 08:52:32 -0300 Message-Id: <20200420115316.18781-17-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200420115316.18781-1-acme@kernel.org> References: <20200420115316.18781-1-acme@kernel.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: Alexey Budankov Update the kernel.rst documentation file with the information related to usage of CAP_PERFMON capability to secure performance monitoring and observability operations in system. Signed-off-by: Alexey Budankov Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: James Morris Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/84c32383-14a2-fa35-16b6-f9e59bd37240@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- Documentation/admin-guide/sysctl/kernel.rst | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 39c95c0e13d3..7e4c28dfc9ca 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -730,7 +730,13 @@ perf_event_paranoid =================== Controls use of the performance events system by unprivileged -users (without CAP_SYS_ADMIN). The default value is 2. +users (without CAP_PERFMON). The default value is 2. + +For backward compatibility reasons access to system performance +monitoring and observability remains open for CAP_SYS_ADMIN +privileged processes but CAP_SYS_ADMIN usage for secure system +performance monitoring and observability operations is discouraged +with respect to CAP_PERFMON use cases. === ================================================================== -1 Allow use of (almost) all events by all users. @@ -739,13 +745,13 @@ users (without CAP_SYS_ADMIN). The default value is 2. ``CAP_IPC_LOCK``. >=0 Disallow ftrace function tracepoint by users without - ``CAP_SYS_ADMIN``. + ``CAP_PERFMON``. - Disallow raw tracepoint access by users without ``CAP_SYS_ADMIN``. + Disallow raw tracepoint access by users without ``CAP_PERFMON``. ->=1 Disallow CPU event access by users without ``CAP_SYS_ADMIN``. +>=1 Disallow CPU event access by users without ``CAP_PERFMON``. ->=2 Disallow kernel profiling by users without ``CAP_SYS_ADMIN``. +>=2 Disallow kernel profiling by users without ``CAP_PERFMON``. === ==================================================================