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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 75860C7112B for ; Sun, 14 Oct 2018 15:33:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46C6120835 for ; Sun, 14 Oct 2018 15:33:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46C6120835 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728433AbeJNXOg (ORCPT ); Sun, 14 Oct 2018 19:14:36 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36284 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728173AbeJNXMF (ORCPT ); Sun, 14 Oct 2018 19:12:05 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1gBiLr-0004cp-DH; Sun, 14 Oct 2018 16:30:43 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLX-0000Vy-CB; Sun, 14 Oct 2018 16:30:23 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Mike Galbraith" , "Ingo Molnar" , "Linus Torvalds" , "Dan Carpenter" , "Thomas Gleixner" , "Peter Zijlstra" Date: Sun, 14 Oct 2018 16:25:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 261/366] sched/core: Fix possible Spectre-v1 indexing for sched_prio_to_weight[] In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Peter Zijlstra commit 7281c8dec8a87685cb54d503d8cceef5a0fc2fdd upstream. > kernel/sched/core.c:6921 cpu_weight_nice_write_s64() warn: potential spectre issue 'sched_prio_to_weight' Userspace controls @nice, so sanitize the value before using it to index an array. Reported-by: Dan Carpenter Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar [bwh: Backported to 3.16: Vulnerable array lookup is in set_load_weight()] Signed-off-by: Ben Hutchings --- --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -74,6 +74,7 @@ #include #include #include +#include #include #include @@ -820,6 +821,8 @@ static void set_load_weight(struct task_ return; } + prio = array_index_nospec(prio, 40); + load->weight = scale_load(prio_to_weight[prio]); load->inv_weight = prio_to_wmult[prio]; }