From patchwork Thu Jan 16 09:47:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masami Ichikawa X-Patchwork-Id: 233850 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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, 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 23DC2C33CB1 for ; Thu, 16 Jan 2020 09:47:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0D8720661 for ; Thu, 16 Jan 2020 09:47:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Uw76ZTf1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729616AbgAPJrq (ORCPT ); Thu, 16 Jan 2020 04:47:46 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:38545 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729388AbgAPJrq (ORCPT ); Thu, 16 Jan 2020 04:47:46 -0500 Received: by mail-pf1-f193.google.com with SMTP id x185so9966970pfc.5; Thu, 16 Jan 2020 01:47:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=l8c+LvOlIaXBLMpBu+gnW139ZMvxJSLj7Fg/MJCqoms=; b=Uw76ZTf1zqvHyf8Pb1Grjc71wgfq1iGAmnabYrBeQrIukT2j1sy4rVufnuSiGrKhma zifubk7YsrNHn0M8EAd8EDjnqA0TEi4gXg4BNUAtasgzFw0SAbtqTa5h3HZCnk5F3FX1 X7xrSfCKmmeu2lufBaFobIDDSlq0fJSHTIMh93+xSzJ/NHgAit3Nbg0skYVYKALg8ahy /bTPieJQuT5hVd1AGweD6V3VNpwxFTtNxi4aitap1JeEgpdTPHKRFG5Sn0/n8Rw7rkf0 a69hrk3BPRsPhNrCjsSudQuaZeHjxTwRuX3JyIC6YLMNPMtgBxFyzCK/GVoa1V+mOTBM pvgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=l8c+LvOlIaXBLMpBu+gnW139ZMvxJSLj7Fg/MJCqoms=; b=sOuBy40FcT8g52m0OSu2f8rjYjrVrK0Ha+MDZtUqePU5tyFSkxHb1+JOWXuLC6ejOZ rjxSZEbmxQdIB6lWs6AWfie8tcLvoa3uIRTen7XkmPTvUhLujr3TyKsL55Njw6SvaWzU ib8CdikCjFsV0t5gi6sy4DAW7BVNHMwSvAHtZsZX7k1h6OjFJW7SF+PRclX8mMLo1XS7 1SzbFU9sqIE/spycw6erUoN197BRd7mG/Y3Pv6q2pQN03CMXp//3ly5DTjfqPwskZmln 4mY0K7eNKO6vQCK1zoppZ0huxSAchKOlduOWgYB7w9YDDYtNkc/DHeCOChc8ZtbPJTAz 569w== X-Gm-Message-State: APjAAAWRJ6kAg7cheQXFnYBY0Z1MOP2F+RS6sANE29ee0+IrB33LNoi3 zX9ErswUONA1BOC55A77xNqZEDGlvEKf4g== X-Google-Smtp-Source: APXvYqzS4tS+2x7b/vzd5Xd9KF74XNEVfPPpaUoOihOElllpwY8XHXjCXoLWjVQUe1B1ZGwevI6YGw== X-Received: by 2002:a62:5c43:: with SMTP id q64mr36911958pfb.194.1579168065677; Thu, 16 Jan 2020 01:47:45 -0800 (PST) Received: from localhost.localdomain (FL1-122-135-105-104.tky.mesh.ad.jp. [122.135.105.104]) by smtp.gmail.com with ESMTPSA id 144sm26366256pfc.124.2020.01.16.01.47.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Jan 2020 01:47:45 -0800 (PST) From: Masami Ichikawa To: rostedt@goodmis.org, mingo@redhat.com Cc: Masami Ichikawa , linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH] tracing: Do not set trace clock if tracefs lockdown is in effect Date: Thu, 16 Jan 2020 18:47:06 +0900 Message-Id: <20200116094707.3846565-1-masami256@gmail.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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: https://bugzilla.redhat.com/show_bug.cgi?id=1788488 Signed-off-by: Masami Ichikawa --- kernel/trace/trace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ddb7e7f5fe8d..5b6ee4aadc26 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9420,6 +9420,11 @@ __init static int tracing_set_default_clock(void) { /* 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"