From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: usb: gadget: storage: Fix Spectre v1 vulnerability From: "Gustavo A. R. Silva" Message-Id: <20181016101645.GA24870@embeddedor.com> Date: Tue, 16 Oct 2018 12:16:45 +0200 To: Felipe Balbi , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" List-ID: bnVtIGNhbiBiZSBpbmRpcmVjdGx5IGNvbnRyb2xsZWQgYnkgdXNlci1zcGFjZSwgaGVuY2UgbGVh ZGluZyB0bwphIHBvdGVudGlhbCBleHBsb2l0YXRpb24gb2YgdGhlIFNwZWN0cmUgdmFyaWFudCAx IHZ1bG5lcmFiaWxpdHkuCgpUaGlzIGlzc3VlIHdhcyBkZXRlY3RlZCB3aXRoIHRoZSBoZWxwIG9m IFNtYXRjaDoKCmRyaXZlcnMvdXNiL2dhZGdldC9mdW5jdGlvbi9mX21hc3Nfc3RvcmFnZS5jOjMx NzcgZnNnX2x1bl9tYWtlKCkgd2FybjoKcG90ZW50aWFsIHNwZWN0cmUgaXNzdWUgJ2ZzZ19vcHRz LT5jb21tb24tPmx1bnMnIFtyXSAobG9jYWwgY2FwKQoKRml4IHRoaXMgYnkgc2FuaXRpemluZyBu dW0gYmVmb3JlIHVzaW5nIGl0IHRvIGluZGV4CmZzZ19vcHRzLT5jb21tb24tPmx1bnMKCk5vdGlj ZSB0aGF0IGdpdmVuIHRoYXQgc3BlY3VsYXRpb24gd2luZG93cyBhcmUgbGFyZ2UsIHRoZSBwb2xp Y3kgaXMKdG8ga2lsbCB0aGUgc3BlY3VsYXRpb24gb24gdGhlIGZpcnN0IGxvYWQgYW5kIG5vdCB3 b3JyeSBpZiBpdCBjYW4gYmUKY29tcGxldGVkIHdpdGggYSBkZXBlbmRlbnQgbG9hZC9zdG9yZSBb MV0uCgpbMV0gaHR0cHM6Ly9tYXJjLmluZm8vP2w9bGludXgta2VybmVsJm09MTUyNDQ5MTMxMTE0 Nzc4Jnc9MgoKQ2M6IHN0YWJsZUB2Z2VyLmtlcm5lbC5vcmcKU2lnbmVkLW9mZi1ieTogR3VzdGF2 byBBLiBSLiBTaWx2YSA8Z3VzdGF2b0BlbWJlZGRlZG9yLmNvbT4KLS0tCiBkcml2ZXJzL3VzYi9n YWRnZXQvZnVuY3Rpb24vZl9tYXNzX3N0b3JhZ2UuYyB8IDMgKysrCiAxIGZpbGUgY2hhbmdlZCwg MyBpbnNlcnRpb25zKCspCgpkaWZmIC0tZ2l0IGEvZHJpdmVycy91c2IvZ2FkZ2V0L2Z1bmN0aW9u L2ZfbWFzc19zdG9yYWdlLmMgYi9kcml2ZXJzL3VzYi9nYWRnZXQvZnVuY3Rpb24vZl9tYXNzX3N0 b3JhZ2UuYwppbmRleCBjYjQwMmU3YS4uMDQzZjk3YSAxMDA2NDQKLS0tIGEvZHJpdmVycy91c2Iv Z2FkZ2V0L2Z1bmN0aW9uL2ZfbWFzc19zdG9yYWdlLmMKKysrIGIvZHJpdmVycy91c2IvZ2FkZ2V0 L2Z1bmN0aW9uL2ZfbWFzc19zdG9yYWdlLmMKQEAgLTIyMSw2ICsyMjEsOCBAQAogI2luY2x1ZGUg PGxpbnV4L3VzYi9nYWRnZXQuaD4KICNpbmNsdWRlIDxsaW51eC91c2IvY29tcG9zaXRlLmg+CiAK KyNpbmNsdWRlIDxsaW51eC9ub3NwZWMuaD4KKwogI2luY2x1ZGUgImNvbmZpZ2ZzLmgiCiAKIApA QCAtMzE1Miw2ICszMTU0LDcgQEAgc3RhdGljIHN0cnVjdCBjb25maWdfZ3JvdXAgKmZzZ19sdW5f bWFrZShzdHJ1Y3QgY29uZmlnX2dyb3VwICpncm91cCwKIAlmc2dfb3B0cyA9IHRvX2ZzZ19vcHRz KCZncm91cC0+Y2dfaXRlbSk7CiAJaWYgKG51bSA+PSBGU0dfTUFYX0xVTlMpCiAJCXJldHVybiBF UlJfUFRSKC1FUkFOR0UpOworCW51bSA9IGFycmF5X2luZGV4X25vc3BlYyhudW0sIEZTR19NQVhf TFVOUyk7CiAKIAltdXRleF9sb2NrKCZmc2dfb3B0cy0+bG9jayk7CiAJaWYgKGZzZ19vcHRzLT5y ZWZjbnQgfHwgZnNnX29wdHMtPmNvbW1vbi0+bHVuc1tudW1dKSB7Cg== 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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 126E3C04EBD for ; Tue, 16 Oct 2018 10:17:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9CFB2145D for ; Tue, 16 Oct 2018 10:17:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C9CFB2145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=embeddedor.com 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 S1727212AbeJPSHS (ORCPT ); Tue, 16 Oct 2018 14:07:18 -0400 Received: from gateway33.websitewelcome.com ([192.185.146.21]:19157 "EHLO gateway33.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727146AbeJPSHS (ORCPT ); Tue, 16 Oct 2018 14:07:18 -0400 Received: from cm15.websitewelcome.com (cm15.websitewelcome.com [100.42.49.9]) by gateway33.websitewelcome.com (Postfix) with ESMTP id 912355858A for ; Tue, 16 Oct 2018 05:17:34 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id CMPCgDIDrtz4jCMPbgL4dO; Tue, 16 Oct 2018 05:17:33 -0500 X-Authority-Reason: nr=8 Received: from lfbn-1-466-13.w86-245.abo.wanadoo.fr ([86.245.173.13]:35640 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gCMPA-000TlY-NM; Tue, 16 Oct 2018 05:16:49 -0500 Date: Tue, 16 Oct 2018 12:16:45 +0200 From: "Gustavo A. R. Silva" To: Felipe Balbi , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] usb: gadget: storage: Fix Spectre v1 vulnerability Message-ID: <20181016101645.GA24870@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) 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: 86.245.173.13 X-Source-L: No X-Exim-ID: 1gCMPA-000TlY-NM X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: lfbn-1-466-13.w86-245.abo.wanadoo.fr (embeddedor) [86.245.173.13]:35640 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 4 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 num can be indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/usb/gadget/function/f_mass_storage.c:3177 fsg_lun_make() warn: potential spectre issue 'fsg_opts->common->luns' [r] (local cap) Fix this by sanitizing num before using it to index fsg_opts->common->luns 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 --- drivers/usb/gadget/function/f_mass_storage.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c index cb402e7a..043f97a 100644 --- a/drivers/usb/gadget/function/f_mass_storage.c +++ b/drivers/usb/gadget/function/f_mass_storage.c @@ -221,6 +221,8 @@ #include #include +#include + #include "configfs.h" @@ -3152,6 +3154,7 @@ static struct config_group *fsg_lun_make(struct config_group *group, fsg_opts = to_fsg_opts(&group->cg_item); if (num >= FSG_MAX_LUNS) return ERR_PTR(-ERANGE); + num = array_index_nospec(num, FSG_MAX_LUNS); mutex_lock(&fsg_opts->lock); if (fsg_opts->refcnt || fsg_opts->common->luns[num]) { -- 2.7.4