From patchwork Mon Apr 13 16:51:47 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: 11485977 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 120BE14B4 for ; Mon, 13 Apr 2020 16:53:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC24B20780 for ; Mon, 13 Apr 2020 16:53:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586796794; bh=8BaehHL+XwhrO6lxdvYxo5llL3H9pC0YPOrBU5W0ve0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qxrWRAcIHYSwmtxO209/V4lDxiUgkxfT+Dci2qlFHn4DKUSku17gstDu1uSuFLgeU 8dSHPTZULl8J318m/Z1E5SfMeHrqMxXRrWuP7zyNUs/cs5Mx0xgptx+pASVc6IZSNi 8RkTot/A9U4BOZyUp59jcxEnA7hiqs6sJbXsivCk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731946AbgDMQxH (ORCPT ); Mon, 13 Apr 2020 12:53:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:45106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731938AbgDMQxF (ORCPT ); Mon, 13 Apr 2020 12:53:05 -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 113652137B; Mon, 13 Apr 2020 16:52:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586796784; bh=8BaehHL+XwhrO6lxdvYxo5llL3H9pC0YPOrBU5W0ve0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tQvCns7bp5ivoVnL8LUena+caaD7KfSakGvU0UeHevRfX9cwVC02zpImFi0db5w5T o+Tmtbxiz8Tc5qrq4rkpquJ0fta2ld3eNSYHqSyQGCq2CqH1vAqyXhBglSBN75p77d 0FLDElKbBSL8JNWtiZgdLL62Q0NlNE644nFtDOR0= 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 10/26] trace/bpf_trace: Open access for CAP_PERFMON privileged process Date: Mon, 13 Apr 2020 13:51:47 -0300 Message-Id: <20200413165203.1816-11-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200413165203.1816-1-acme@kernel.org> References: <20200413165203.1816-1-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 68250d433bd7..770b742fc922 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1416,7 +1416,7 @@ 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;