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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 6DAF9C67839 for ; Thu, 13 Dec 2018 08:13:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3371020849 for ; Thu, 13 Dec 2018 08:13:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3371020849 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de 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 S1727323AbeLMINq (ORCPT ); Thu, 13 Dec 2018 03:13:46 -0500 Received: from mx2.suse.de ([195.135.220.15]:43728 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727042AbeLMINp (ORCPT ); Thu, 13 Dec 2018 03:13:45 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 4DE1AADD6; Thu, 13 Dec 2018 08:13:44 +0000 (UTC) Date: Thu, 13 Dec 2018 09:13:44 +0100 Message-ID: From: Takashi Iwai To: " Gustavo A. R. Silva " Cc: "Jaroslav Kysela" , , Subject: Re: [PATCH] ALSA: emux_hwdep: Fix potential Spectre v1 vulnerabilities In-Reply-To: <20181212172049.GA22723@embeddedor> References: <20181212172049.GA22723@embeddedor> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/26 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 12 Dec 2018 18:20:49 +0100, Gustavo A. R. Silva wrote: > > info.mode and info.port are indirectly controlled by user-space, > hence leading to a potential exploitation of the Spectre variant 1 > vulnerability. > > These issues were detected with the help of Smatch: > > sound/synth/emux/emux_hwdep.c:72 snd_emux_hwdep_misc_mode() warn: potential spectre issue 'emu->portptrs[i]->ctrls' [w] (local cap) > sound/synth/emux/emux_hwdep.c:75 snd_emux_hwdep_misc_mode() warn: potential spectre issue 'emu->portptrs' [w] (local cap) > sound/synth/emux/emux_hwdep.c:75 snd_emux_hwdep_misc_mode() warn: potential spectre issue 'emu->portptrs[info.port]->ctrls' [w] (local cap) > > Fix this by sanitizing both info.mode and info.port before using them > to index emu->portptrs[i]->ctrls, emu->portptrs[info.port]->ctrls and > emu->portptrs. > > Notice that given that speculation windows are large, the policy is > to kill the speculation on the first load and not worry if it can be > completed with a dependent load/store [1]. > > [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 > > Cc: stable@vger.kernel.org > Signed-off-by: Gustavo A. R. Silva Applied now (with moving the linux/nospec.h in a more appropriate line). thanks, Takashi