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From: Alexey Budankov <alexey.budankov@linux.intel.com>
To: James Morris <jmorris@namei.org>, Serge Hallyn <serge@hallyn.com>,
	Stephen Smalley <sds@tycho.nsa.gov>,
	Peter Zijlstra <peterz@infradead.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	"joonas.lahtinen@linux.intel.com"
	<joonas.lahtinen@linux.intel.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Will Deacon <will@kernel.org>, Paul Mackerras <paulus@samba.org>,
	Helge Deller <deller@gmx.de>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>,
	Stephane Eranian <eranian@google.com>,
	Igor Lubashev <ilubashe@akamai.com>, Jiri Olsa <jolsa@redhat.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	"intel-gfx@lists.freedesktop.org"
	<intel-gfx@lists.freedesktop.org>,
	"linux-security-module@vger.kernel.org" 
	<linux-security-module@vger.kernel.org>,
	"selinux@vger.kernel.org" <selinux@vger.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	"linux-parisc@vger.kernel.org" <linux-parisc@vger.kernel.org>,
	oprofile-list@lists.sf.net,
	"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	linux-man@vger.kernel.org
Subject: [PATCH v7 03/12] perf/core: open access to probes for CAP_PERFMON privileged process
Date: Mon, 17 Feb 2020 11:07:37 +0300
Message-ID: <3364fa26-b5d1-1808-aaee-c057f26e0eb4@linux.intel.com> (raw)
In-Reply-To: <c8de937a-0b3a-7147-f5ef-69f467e87a13@linux.intel.com>


Open access to monitoring via kprobes and uprobes and eBPF tracing for
CAP_PERFMON privileged process. Providing the access under CAP_PERFMON
capability singly, without the rest of CAP_SYS_ADMIN credentials,
excludes chances to misuse the credentials and makes operation more
secure.

perf kprobes and uprobes are used by ftrace and eBPF. perf probe uses
ftrace to define new kprobe events, and those events are treated as
tracepoint events. eBPF defines new probes via perf_event_open interface
and then the probes are used in eBPF tracing.

CAP_PERFMON implements the principal of least privilege for performance
monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39
principle of least privilege: A security design principle that states
that a process or program be granted only those privileges (e.g.,
capabilities) necessary to accomplish its legitimate function, and only
for the time that such privileges are actually required)

For backward compatibility reasons access to perf_events subsystem
remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN
usage for secure perf_events monitoring is discouraged with respect to
CAP_PERFMON capability.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 kernel/events/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 46464367c47a..4564caa2c527 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9107,7 +9107,7 @@ static int perf_kprobe_event_init(struct perf_event *event)
 	if (event->attr.type != perf_kprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
@@ -9167,7 +9167,7 @@ static int perf_uprobe_event_init(struct perf_event *event)
 	if (event->attr.type != perf_uprobe.type)
 		return -ENOENT;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!perfmon_capable())
 		return -EACCES;
 
 	/*
-- 
2.20.1



  parent reply index

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-17  8:02 [PATCH v7 00/12] Introduce CAP_PERFMON to secure system performance monitoring and observability Alexey Budankov
2020-02-17  8:06 ` [PATCH v7 01/12] capabilities: introduce CAP_PERFMON to kernel and user space Alexey Budankov
2020-02-18 18:22   ` Stephen Smalley
2020-02-18 19:21   ` James Morris
2020-02-19  7:54     ` Alexey Budankov
2020-02-17  8:06 ` [PATCH v7 02/12] perf/core: open access to the core for CAP_PERFMON privileged process Alexey Budankov
2020-02-18 19:22   ` James Morris
2020-02-17  8:07 ` Alexey Budankov [this message]
2020-02-18 19:22   ` [PATCH v7 03/12] perf/core: open access to probes " James Morris
2020-02-17  8:08 ` [PATCH v7 04/12] perf tool: extend Perf tool with CAP_PERFMON capability support Alexey Budankov
2020-02-18 19:24   ` James Morris
2020-02-17  8:08 ` [PATCH v7 05/12] drm/i915/perf: open access for CAP_PERFMON privileged process Alexey Budankov
2020-02-18 19:25   ` James Morris
2020-02-17  8:09 ` [PATCH v7 06/12] trace/bpf_trace: " Alexey Budankov
2020-02-18 19:25   ` James Morris
2020-02-17  8:10 ` [PATCH v7 07/12] powerpc/perf: " Alexey Budankov
2020-02-18 19:28   ` James Morris
2020-02-17  8:10 ` [PATCH v7 08/12] parisc/perf: " Alexey Budankov
2020-02-18 19:29   ` James Morris
2020-02-17  8:11 ` [PATCH v7 09/12] drivers/perf: " Alexey Budankov
2020-02-18 19:43   ` James Morris
2020-02-17  8:12 ` [PATCH v7 10/12] drivers/oprofile: " Alexey Budankov
2020-02-18 19:44   ` James Morris
2020-02-17  8:12 ` [PATCH v7 11/12] doc/admin-guide: update perf-security.rst with CAP_PERFMON information Alexey Budankov
2020-02-17  8:13 ` [PATCH v7 12/12] doc/admin-guide: update kernel.rst " Alexey Budankov
2020-02-25  9:55 ` [PATCH v7 00/12] Introduce CAP_PERFMON to secure system performance monitoring and observability Alexey Budankov
2020-03-02  0:19   ` [Intel-gfx] " Serge Hallyn
2020-03-02 19:44     ` James Morris
2020-03-26 23:28     ` James Morris

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