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=-20.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 29534C4338F for ; Mon, 2 Aug 2021 14:13:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CDC160E09 for ; Mon, 2 Aug 2021 14:13:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236487AbhHBONJ (ORCPT ); Mon, 2 Aug 2021 10:13:09 -0400 Received: from gateway20.websitewelcome.com ([192.185.47.18]:33135 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235282AbhHBOHr (ORCPT ); Mon, 2 Aug 2021 10:07:47 -0400 X-Greylist: delayed 1425 seconds by postgrey-1.27 at vger.kernel.org; Mon, 02 Aug 2021 10:07:47 EDT Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway20.websitewelcome.com (Postfix) with ESMTP id 5396D400D9217 for ; Mon, 2 Aug 2021 08:27:28 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id AYENmvRsmK61iAYENm3JQg; Mon, 02 Aug 2021 08:43:47 -0500 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ofCX79+Rdf3KA3ygQd5aThXKKbcOK34wLcXaAGModx0=; b=Rw0CtDE1sjh2NVCk9V6FIHr2ha fm459NwtYD/fFi5HNqYS7vFodXN3cuSisRlKnLm4Tdffp66F/Il285vyvcvIJ4qFA+frcMr9mezf4 +hqngJI5USHqj+hxTyx8uxCXuMHDZ2rg+T6sMnUkqMUSgGS2OT3QPnUN8u8Rp6vs9NcBVAjZUoW2V GGHqg1FDzFn1qFj7zUea+eNNphWNYuhOtiLMNqLYnqCgwB3saNkSgmwfUnZoGz0Ly4Lpfy+SD0GQG 2AYe5Knt9xfNY2w5TULaJGjUEmK9VTH7/Io3W1z4rzObmbJOsZ2xy39aiNWTCypZ7WGsbHrv06uqb hdjeKb1w==; Received: from 187-162-31-110.static.axtel.net ([187.162.31.110]:56648 helo=[192.168.15.8]) by gator4166.hostgator.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1mAYEM-001O0n-Lf; Mon, 02 Aug 2021 08:43:46 -0500 Subject: Re: [PATCH v2 1/2] media: staging/intel-ipu3: css: Fix wrong size comparison To: Sakari Ailus , "Gustavo A. R. Silva" Cc: linux-kernel@vger.kernel.org, Yong Zhi , Bingbu Cao , Tianshu Qiu , Mauro Carvalho Chehab , Greg Kroah-Hartman , linux-media@vger.kernel.org, linux-staging@lists.linux.dev, linux-hardening@vger.kernel.org, Dan Carpenter References: <184d96f95d6261b1a91704eb68adbd0a2e1c2cc2.1627646101.git.gustavoars@kernel.org> <20210802060546.GL3@paasikivi.fi.intel.com> From: "Gustavo A. R. Silva" Message-ID: <3c9ac43d-09ca-e5d5-83a8-7b6d23928763@embeddedor.com> Date: Mon, 2 Aug 2021 08:46:20 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210802060546.GL3@paasikivi.fi.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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: 187.162.31.110 X-Source-L: No X-Exim-ID: 1mAYEM-001O0n-Lf X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 187-162-31-110.static.axtel.net ([192.168.15.8]) [187.162.31.110]:56648 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 11 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Hi Sakari, On 8/2/21 01:05, Sakari Ailus wrote: > Hi Gustavo, > > I missed you already had sent v2... > > On Fri, Jul 30, 2021 at 07:08:13AM -0500, Gustavo A. R. Silva wrote: >> There is a wrong comparison of the total size of the loaded firmware >> css->fw->size with the size of a pointer to struct imgu_fw_header. >> >> Fix this by using the right operand 'struct imgu_fw_header' for >> sizeof, instead of 'struct imgu_fw_header *' and turn binary_header >> into a flexible-array member. Also, adjust the relational operator >> to be '<=' instead of '<', as it seems that the intention of the >> comparison is to determine if the loaded firmware contains any >> 'struct imgu_fw_info' items in the binary_header[] array than merely >> the file_header (struct imgu_fw_bi_file_h). >> >> The replacement of the one-element array with a flexible-array member >> also help with the ongoing efforts to globally enable -Warray-bounds >> and get us closer to being able to tighten the FORTIFY_SOURCE routines >> on memcpy(). >> >> Link: https://github.com/KSPP/linux/issues/79 >> Link: https://github.com/KSPP/linux/issues/109 >> Fixes: 09d290f0ba21 ("media: staging/intel-ipu3: css: Add support for firmware management") >> Cc: stable@vger.kernel.org >> Signed-off-by: Gustavo A. R. Silva >> --- >> >> It'd be just great if someone that knows this code better can confirm >> these changes are correct. In particular the adjustment of the >> relational operator. Thanks! >> >> Changes in v2: >> - Use flexible array and adjust relational operator, accordingly. > > The operator was just correct. The check is just there to see the firmware > is at least as large as the struct as which it is being accessed. I'm a bit confused, so based on your reply to v1 of this series, this patch is now correct, right? The operator in v1 _was_ correct as long as the one-element array wasn't transformed into a flexible array, right? Notice that generally speaking flexible-array members don't occupy space in the containing structure: $ pahole -C imgu_fw_header drivers/staging/media/ipu3/ipu3-css-fw.o struct imgu_fw_header { struct imgu_fw_bi_file_h file_header; /* 0 72 */ /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */ struct imgu_fw_info binary_header[] __attribute__((__aligned__(8))); /* 72 0 */ /* size: 72, cachelines: 2, members: 2 */ /* forced alignments: 1 */ /* last cacheline: 8 bytes */ } __attribute__((__aligned__(8))); $ pahole -C imgu_fw_header drivers/staging/media/ipu3/ipu3-css-fw.o struct imgu_fw_header { struct imgu_fw_bi_file_h file_header; /* 0 72 */ /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */ struct imgu_fw_info binary_header[1] __attribute__((__aligned__(8))); /* 72 1200 */ /* size: 1272, cachelines: 20, members: 2 */ /* forced alignments: 1 */ /* last cacheline: 56 bytes */ } __attribute__((__aligned__(8))); So, now that the flexible array transformation is included in the same patch as the bugfix, the operator is changed from '<' to '<=' Can you please confirm if this v2 is now correct? if so, it'd be great to have your Reviewed-by tag. :) Thanks! -- Gustavo > >> - Update changelog text. >> >> drivers/staging/media/ipu3/ipu3-css-fw.c | 2 +- >> drivers/staging/media/ipu3/ipu3-css-fw.h | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/staging/media/ipu3/ipu3-css-fw.c b/drivers/staging/media/ipu3/ipu3-css-fw.c >> index 45aff76198e2..630cb5186b48 100644 >> --- a/drivers/staging/media/ipu3/ipu3-css-fw.c >> +++ b/drivers/staging/media/ipu3/ipu3-css-fw.c >> @@ -124,7 +124,7 @@ int imgu_css_fw_init(struct imgu_css *css) >> /* Check and display fw header info */ >> >> css->fwp = (struct imgu_fw_header *)css->fw->data; >> - if (css->fw->size < sizeof(struct imgu_fw_header *) || >> + if (css->fw->size <= sizeof(struct imgu_fw_header) || >> css->fwp->file_header.h_size != sizeof(struct imgu_fw_bi_file_h)) >> goto bad_fw; >> if (sizeof(struct imgu_fw_bi_file_h) + >> diff --git a/drivers/staging/media/ipu3/ipu3-css-fw.h b/drivers/staging/media/ipu3/ipu3-css-fw.h >> index 3c078f15a295..c0bc57fd678a 100644 >> --- a/drivers/staging/media/ipu3/ipu3-css-fw.h >> +++ b/drivers/staging/media/ipu3/ipu3-css-fw.h >> @@ -171,7 +171,7 @@ struct imgu_fw_bi_file_h { >> >> struct imgu_fw_header { >> struct imgu_fw_bi_file_h file_header; >> - struct imgu_fw_info binary_header[1]; /* binary_nr items */ >> + struct imgu_fw_info binary_header[]; /* binary_nr items */ >> }; >> >> /******************* Firmware functions *******************/ >