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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 3C8F4C433DB for ; Thu, 21 Jan 2021 22:44:13 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 775AD23A56 for ; Thu, 21 Jan 2021 22:44:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 775AD23A56 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37704 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l2igV-000159-Iv for qemu-devel@archiver.kernel.org; Thu, 21 Jan 2021 17:44:11 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:48182) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l2if5-0000VW-RC for qemu-devel@nongnu.org; Thu, 21 Jan 2021 17:42:43 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:59819) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l2if3-0003XU-Bd for qemu-devel@nongnu.org; Thu, 21 Jan 2021 17:42:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611268959; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FW05jpBQUjIo15fntQKf+Sbu9CtoXO1s1tIeEo6y38g=; b=J0Y7dpKv1MFloAqIm1RqyY2yt7z+r7qxvjDEhrPk32cOo+3BJZg2+c7ZeNz7ivOCoaqB5W mjNxKZeytFq1G24jkawBCIBg7rOUKN4/HSf063A45w5soRLjRk/7vqP1UpfW1nSiQUyRoN 07IL+so67k19VQeKHFZWviWQ1neeh/Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-181-p5ZgcazAMgOEV4lccRgsJQ-1; Thu, 21 Jan 2021 17:42:36 -0500 X-MC-Unique: p5ZgcazAMgOEV4lccRgsJQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AF6A7802B45; Thu, 21 Jan 2021 22:42:34 +0000 (UTC) Received: from [10.3.113.116] (ovpn-113-116.phx2.redhat.com [10.3.113.116]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9E2AB60BF3; Thu, 21 Jan 2021 22:42:30 +0000 (UTC) Subject: Re: [PATCH v4 03/16] block: fix theoretical overflow in bdrv_init_padding() To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20201211183934.169161-1-vsementsov@virtuozzo.com> <20201211183934.169161-4-vsementsov@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <1856d39a-0a11-85cc-8b3a-c6322f8f838d@redhat.com> Date: Thu, 21 Jan 2021 16:42:30 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20201211183934.169161-4-vsementsov@virtuozzo.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.168, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: fam@euphon.net, kwolf@redhat.com, berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 12/11/20 12:39 PM, Vladimir Sementsov-Ogievskiy wrote: > Calculation of sum may theoretically overflow, so use 64bit type and > add some good assertions. > > Use int64_t constantly. > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > block/io.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/block/io.c b/block/io.c > index 21e8a50725..d9bc67f1b0 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -1537,8 +1537,12 @@ static bool bdrv_init_padding(BlockDriverState *bs, > int64_t offset, int64_t bytes, > BdrvRequestPadding *pad) > { > - uint64_t align = bs->bl.request_alignment; > - size_t sum; > + int64_t align = bs->bl.request_alignment; > + int64_t sum; > + > + bdrv_check_request(offset, bytes, &error_abort); > + assert(align <= INT_MAX); /* documented in block/block_int.h */ > + assert(align * 2 <= SIZE_MAX); /* so we can allocate the buffer */ Would look better as assert(align <= SIZE_MAX / 2); but not technically wrong as written because the earlier line proved align is less than 32 bits so align*2 can't overflow 63 bits. Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org