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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 12B36C2D0DB for ; Tue, 28 Jan 2020 14:06:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF81C22522 for ; Tue, 28 Jan 2020 14:06:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220400; bh=QuURjKC5p50u5pwWW0BohDmU93jrwtJYbv5Osn5F+hs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uFc3eYyQzgtZvLKxpqGqnyMPeOqPetK3nUtn6oGHokNhNUnFmue1gqi/ICkdG5eOA fFuHF0U+Oa/APeMGJ5+4j0QWzu+88RNCLvS1rt07HYsPkz5BvLsJXMY4Ubn2EHnel3 vfqDAPXWxtCB5GCEGi6qp04vl/lslTDwxtyXrMrE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728088AbgA1OEa (ORCPT ); Tue, 28 Jan 2020 09:04:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:51510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728061AbgA1OEX (ORCPT ); Tue, 28 Jan 2020 09:04:23 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 030EF24688; Tue, 28 Jan 2020 14:04:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580220262; bh=QuURjKC5p50u5pwWW0BohDmU93jrwtJYbv5Osn5F+hs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QwGKGppLiRhu06bF6U5DbjMSZpoizbjbc69NAYQ0mU7o8udBq2zN58Q4cbrxJJW2+ UkN9NJcUAAdLsGuoGpYPcgxVWqMUYD/sY2Rpu6t+KzRx+odchLIsJYP9qviX2Sv0+M WopQ5CvU9vcJHjxyIhZ2gTpg5VPcBxVtZo0JQVWg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Ichikawa , "Steven Rostedt (VMware)" Subject: [PATCH 5.4 044/104] tracing: Do not set trace clock if tracefs lockdown is in effect Date: Tue, 28 Jan 2020 15:00:05 +0100 Message-Id: <20200128135823.801981789@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135817.238524998@linuxfoundation.org> References: <20200128135817.238524998@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Masami Ichikawa commit bf24daac8f2bd5b8affaec03c2be1d20bcdd6837 upstream. When trace_clock option is not set and unstable clcok detected, tracing_set_default_clock() sets trace_clock(ThinkPad A285 is one of case). In that case, if lockdown is in effect, null pointer dereference error happens in ring_buffer_set_clock(). Link: http://lkml.kernel.org/r/20200116131236.3866925-1-masami256@gmail.com Cc: stable@vger.kernel.org Fixes: 17911ff38aa58 ("tracing: Add locked_down checks to the open calls of files created for tracefs") Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1788488 Signed-off-by: Masami Ichikawa Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9270,6 +9270,11 @@ __init static int tracing_set_default_cl { /* sched_clock_stable() is determined in late_initcall */ if (!trace_boot_clock && !sched_clock_stable()) { + if (security_locked_down(LOCKDOWN_TRACEFS)) { + pr_warn("Can not set tracing clock due to lockdown\n"); + return -EPERM; + } + printk(KERN_WARNING "Unstable clock detected, switching default tracing clock to \"global\"\n" "If you want to keep using the local clock, then add:\n"