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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 CC5E5C4321D for ; Thu, 23 Aug 2018 08:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 901772083A for ; Thu, 23 Aug 2018 08:41:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 901772083A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S1732464AbeHWMKA (ORCPT ); Thu, 23 Aug 2018 08:10:00 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49860 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729381AbeHWMJ7 (ORCPT ); Thu, 23 Aug 2018 08:09:59 -0400 Received: from localhost (5355525A.cm-6-6b.dynamic.ziggo.nl [83.85.82.90]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 0F6D88B1; Thu, 23 Aug 2018 08:41:22 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Garry , Tejun Heo , Sasha Levin Subject: [PATCH 4.17 050/324] libahci: Fix possible Spectre-v1 pmp indexing in ahci_led_store() Date: Thu, 23 Aug 2018 09:51:56 +0200 Message-Id: <20180823074958.298177876@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180823074955.885811006@linuxfoundation.org> References: <20180823074955.885811006@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Garry [ Upstream commit fae2a63737e5973f1426bc139935a0f42e232844 ] Currently smatch warns of possible Spectre-V1 issue in ahci_led_store(): drivers/ata/libahci.c:1150 ahci_led_store() warn: potential spectre issue 'pp->em_priv' (local cap) Userspace controls @pmp from following callchain: em_message->store() ->ata_scsi_em_message_store() -->ap->ops->em_store() --->ahci_led_store() After the mask+shift @pmp is effectively an 8b value, which is used to index into an array of length 8, so sanitize the array index. Signed-off-by: John Garry Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/ata/libahci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -1146,10 +1147,12 @@ static ssize_t ahci_led_store(struct ata /* get the slot number from the message */ pmp = (state & EM_MSG_LED_PMP_SLOT) >> 8; - if (pmp < EM_MAX_SLOTS) + if (pmp < EM_MAX_SLOTS) { + pmp = array_index_nospec(pmp, EM_MAX_SLOTS); emp = &pp->em_priv[pmp]; - else + } else { return -EINVAL; + } /* mask off the activity bits if we are in sw_activity * mode, user should turn off sw_activity before setting