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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 0CF8BC43444 for ; Wed, 9 Jan 2019 23:39:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC9E52075C for ; Wed, 9 Jan 2019 23:39:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726680AbfAIXjK (ORCPT ); Wed, 9 Jan 2019 18:39:10 -0500 Received: from gateway21.websitewelcome.com ([192.185.46.109]:49643 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726505AbfAIXjK (ORCPT ); Wed, 9 Jan 2019 18:39:10 -0500 Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway21.websitewelcome.com (Postfix) with ESMTP id 79339400DAF7F for ; Wed, 9 Jan 2019 17:39:08 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id hNREgJgQQ2PzOhNREgy0c3; Wed, 09 Jan 2019 17:39:08 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=50446 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1ghNRD-002ypT-NB; Wed, 09 Jan 2019 17:39:07 -0600 Date: Wed, 9 Jan 2019 17:39:06 -0600 From: "Gustavo A. R. Silva" To: Corey Minyard , Arnd Bergmann , Greg Kroah-Hartman Cc: openipmi-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] ipmi: msghandler: Fix potential Spectre v1 vulnerabilities Message-ID: <20190109233906.GA4170@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.130.205 X-Source-L: No X-Exim-ID: 1ghNRD-002ypT-NB X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:50446 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org channel and addr->channel 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: drivers/char/ipmi/ipmi_msghandler.c:1381 ipmi_set_my_address() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap) drivers/char/ipmi/ipmi_msghandler.c:1401 ipmi_get_my_address() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap) drivers/char/ipmi/ipmi_msghandler.c:1421 ipmi_set_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [w] (local cap) drivers/char/ipmi/ipmi_msghandler.c:1441 ipmi_get_my_LUN() warn: potential spectre issue 'user->intf->addrinfo' [r] (local cap) drivers/char/ipmi/ipmi_msghandler.c:2260 check_addr() warn: potential spectre issue 'intf->addrinfo' [r] (local cap) Fix this by sanitizing channel and addr->channel before using them to index user->intf->addrinfo and intf->addrinfo, correspondingly. 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://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/ Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva --- drivers/char/ipmi/ipmi_msghandler.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 480d9bd7e1ab..557e98d9364d 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -32,6 +32,7 @@ #include #include #include +#include #define IPMI_DRIVER_VERSION "39.2" @@ -1375,10 +1376,12 @@ int ipmi_set_my_address(struct ipmi_user *user, if (!user) return -ENODEV; - if (channel >= IPMI_MAX_CHANNELS) + if (channel >= IPMI_MAX_CHANNELS) { rv = -EINVAL; - else + } else { + channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); user->intf->addrinfo[channel].address = address; + } release_ipmi_user(user, index); return rv; @@ -1395,10 +1398,12 @@ int ipmi_get_my_address(struct ipmi_user *user, if (!user) return -ENODEV; - if (channel >= IPMI_MAX_CHANNELS) + if (channel >= IPMI_MAX_CHANNELS) { rv = -EINVAL; - else + } else { + channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); *address = user->intf->addrinfo[channel].address; + } release_ipmi_user(user, index); return rv; @@ -1415,10 +1420,12 @@ int ipmi_set_my_LUN(struct ipmi_user *user, if (!user) return -ENODEV; - if (channel >= IPMI_MAX_CHANNELS) + if (channel >= IPMI_MAX_CHANNELS) { rv = -EINVAL; - else + } else { + channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); user->intf->addrinfo[channel].lun = LUN & 0x3; + } release_ipmi_user(user, index); return rv; @@ -1435,10 +1442,12 @@ int ipmi_get_my_LUN(struct ipmi_user *user, if (!user) return -ENODEV; - if (channel >= IPMI_MAX_CHANNELS) + if (channel >= IPMI_MAX_CHANNELS) { rv = -EINVAL; - else + } else { + channel = array_index_nospec(channel, IPMI_MAX_CHANNELS); *address = user->intf->addrinfo[channel].lun; + } release_ipmi_user(user, index); return rv; @@ -2257,6 +2266,7 @@ static int check_addr(struct ipmi_smi *intf, { if (addr->channel >= IPMI_MAX_CHANNELS) return -EINVAL; + addr->channel = array_index_nospec(addr->channel, IPMI_MAX_CHANNELS); *lun = intf->addrinfo[addr->channel].lun; *saddr = intf->addrinfo[addr->channel].address; return 0; -- 2.20.1