From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50DA5C433FF for ; Mon, 12 Aug 2019 09:13:57 +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 25AA62085A for ; Mon, 12 Aug 2019 09:13:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nZ/Xgq89" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 25AA62085A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.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:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0m6iBa3EghMK1WAXv5b5YQ/D0TBz5y2IjYJ4fS4q2XA=; b=nZ/Xgq891qIdZ4 wDwVJ84V9TYn2NQ8rXkCyKTkPN5lpleJvafExlJm2xgWpDH6kJRQ0dU8E4f5i4f8CdazMc1yCXLhO 1ssX5AhKnSHH1Xod3ueK1uq49qkY3hdSsv8HM4OIhBpEATjvevioyXBwLQTD8J705TeOn0nas80R4 XKO0XkiWlfZTVIQ0XQ5cwjXzwAuPK4KSCLWYFxPMIqwQ4niWxr1YeAJiMWtqioh0lFIoq4CzqXUe3 bJGZ/2lieIYxOkZgxOZ6EjlYbn9v22R7fH3cbHg88YOdUdmDffeydf78DHm3ptHXkUQVZy24IU0wV MGF+aEfteEIZOEremlGw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hx6Oq-0006tF-9u; Mon, 12 Aug 2019 09:13:56 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hx6Om-0006sY-DE for linux-arm-kernel@lists.infradead.org; Mon, 12 Aug 2019 09:13:54 +0000 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4FB5030BCB86; Mon, 12 Aug 2019 09:13:51 +0000 (UTC) Received: from krava (unknown [10.43.17.33]) by smtp.corp.redhat.com (Postfix) with SMTP id D192F19C65; Mon, 12 Aug 2019 09:13:48 +0000 (UTC) Date: Mon, 12 Aug 2019 11:13:48 +0200 From: Jiri Olsa To: Igor Lubashev Subject: Re: [PATCH v3 0/4] perf: Use capabilities instead of uid and euid Message-ID: <20190812091348.GA11946@krava> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Mon, 12 Aug 2019 09:13:51 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190812_021352_479981_3D0C2F48 X-CRM114-Status: GOOD ( 22.45 ) 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: Mathieu Poirier , Suzuki K Poulose , Peter Zijlstra , Alexey Budankov , linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , James Morris , Alexander Shishkin , Ingo Molnar , Namhyung Kim , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Aug 07, 2019 at 10:44:13AM -0400, Igor Lubashev wrote: > Series v1: https://lkml.kernel.org/lkml/1562112605-6235-1-git-send-email-ilubashe@akamai.com > > > Kernel is using capabilities instead of uid and euid to restrict access to > kernel pointers and tracing facilities. This patch series updates the perf to > better match the security model used by the kernel. > > This series enables instructions in Documentation/admin-guide/perf-security.rst > to actually work, even when kernel.perf_event_paranoid=2 and > kernel.kptr_restrict=1. > > The series consists of four patches: > > 01: perf: Add capability-related utilities > Add utility functions to check capabilities and perf_event_paranoid checks, > if libcap-dev[el] is available. (Otherwise, assume no capabilities.) > > 02: perf: Use CAP_SYS_ADMIN with perf_event_paranoid checks > Replace the use of euid==0 with a check for CAP_SYS_ADMIN whenever > perf_event_paranoid level is verified. > > 03: perf: Use CAP_SYSLOG with kptr_restrict checks > Replace the use of uid and euid with a check for CAP_SYSLOG when > kptr_restrict is verified (similar to kernel/kallsyms.c and lib/vsprintf.c). > Consult perf_event_paranoid when kptr_restrict==0 (see kernel/kallsyms.c). > > 04: perf: Use CAP_SYS_ADMIN instead of euid==0 with ftrace > Replace the use of euid==0 with a check for CAP_SYS_ADMIN before mounting > debugfs for ftrace. > > I tested this by following Documentation/admin-guide/perf-security.rst > guidelines and setting sysctls: > > kernel.perf_event_paranoid=2 > kernel.kptr_restrict=1 > > As an unprivileged user who is in perf_users group (setup via instructions > above), I executed: > perf record -a -- sleep 1 > > Without the patch, perf record did not capture any kernel functions. > With the patch, perf included all kernel functions. > > > Changelog: > v3: * Fix arm64 compilation (thanks, Alexey and Jiri) Acked-by: Jiri Olsa thanks, jirka > v2: * Added a build feature check for libcap-dev[el] as suggested by Arnaldo > > > Igor Lubashev (4): > perf: Add capability-related utilities > perf: Use CAP_SYS_ADMIN with perf_event_paranoid checks > perf: Use CAP_SYSLOG with kptr_restrict checks > perf: Use CAP_SYS_ADMIN instead of euid==0 with ftrace > > tools/build/Makefile.feature | 2 ++ > tools/build/feature/Makefile | 4 ++++ > tools/build/feature/test-libcap.c | 20 ++++++++++++++++++++ > tools/perf/Makefile.config | 11 +++++++++++ > tools/perf/Makefile.perf | 2 ++ > tools/perf/arch/arm/util/cs-etm.c | 3 ++- > tools/perf/arch/arm64/util/arm-spe.c | 3 ++- > tools/perf/arch/x86/util/intel-bts.c | 3 ++- > tools/perf/arch/x86/util/intel-pt.c | 2 +- > tools/perf/builtin-ftrace.c | 4 +++- > tools/perf/util/Build | 2 ++ > tools/perf/util/cap.c | 29 +++++++++++++++++++++++++++++ > tools/perf/util/cap.h | 24 ++++++++++++++++++++++++ > tools/perf/util/event.h | 1 + > tools/perf/util/evsel.c | 2 +- > tools/perf/util/python-ext-sources | 1 + > tools/perf/util/symbol.c | 15 +++++++++++---- > tools/perf/util/util.c | 9 +++++++++ > 18 files changed, 127 insertions(+), 10 deletions(-) > create mode 100644 tools/build/feature/test-libcap.c > create mode 100644 tools/perf/util/cap.c > create mode 100644 tools/perf/util/cap.h > > -- > 2.7.4 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel