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=-7.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A8FF8C433B4 for ; Mon, 17 May 2021 19:42:55 +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 520A960FF3 for ; Mon, 17 May 2021 19:42:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 520A960FF3 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]:53428 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lij8g-00025X-Gq for qemu-devel@archiver.kernel.org; Mon, 17 May 2021 15:42:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57992) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lij7v-0000dF-7y for qemu-devel@nongnu.org; Mon, 17 May 2021 15:42:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:30692) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lij7s-00064c-Fd for qemu-devel@nongnu.org; Mon, 17 May 2021 15:42:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621280523; 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=l5GI9dTaQzQQJlgy4ievWmUEo+nMFhWvvjggbzS9Dkk=; b=OsxMR4BxRtZmcATIrHx0hqoZoPX89dG59+/mdiIj7iznlCvEgESq87Ky4SVZ40X1BaZYhK hiGnb12OScN3DnxEEx1PQaX+qrynlR1LiWalOFm1dn6mag5cygkEeZmBl2Zlwj9DEaD4je bh036QH+GoYqm7QPxjHMcnAC/z5+N1c= 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-174-scvIheWdNciMSciEZvcUCA-1; Mon, 17 May 2021 15:42:01 -0400 X-MC-Unique: scvIheWdNciMSciEZvcUCA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AFF948049C5; Mon, 17 May 2021 19:42:00 +0000 (UTC) Received: from [10.10.117.64] (ovpn-117-64.rdu2.redhat.com [10.10.117.64]) by smtp.corp.redhat.com (Postfix) with ESMTP id 788FB60CD0; Mon, 17 May 2021 19:41:59 +0000 (UTC) Subject: Re: [PATCH] fdc: check drive block device before usage (CVE-2021-20196) To: Alexander Bulekov , P J P References: <20210123100345.642933-1-ppandit@redhat.com> <20210123174725.slddy75u7egga43n@mozz.bu.edu> <20210123175245.rpckqnoihjtsv6lp@mozz.bu.edu> From: John Snow Message-ID: <3fc646ae-e34d-dbcd-204b-156f99ce75c2@redhat.com> Date: Mon, 17 May 2021 15:41:58 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210123175245.rpckqnoihjtsv6lp@mozz.bu.edu> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.374, 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_H4=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: Gaoning Pan , QEMU Developers , Prasad J Pandit Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 1/23/21 12:52 PM, Alexander Bulekov wrote: > On 210123 1247, Alexander Bulekov wrote: >> Hello, >> Here is a reproducer for this bug found by the OSS-Fuzz fuzzer: >> >> cat << EOF | qemu-system-i386 -display none -machine accel=qtest \ >> -m 512M -machine pc -device floppy,unit=1,id=floppy0,drive=disk0 \ >> -drive id=disk0,file=null-co://,file.read-zeroes=on,if=none,format=raw \ >> -qtest stdio >> outw 0x3f4 0x2500 >> outb 0x3f5 0x81 >> outb 0x3f5 0x0 >> outb 0x3f5 0x0 >> outb 0x3f5 0x0 >> outw 0x3f4 0x0 >> outw 0x3f4 0x4000 >> outw 0x3f4 0x13 >> outb 0x3f5 0x1 >> outw 0x3f2 0x1405 >> outw 0x3f4 0x0 >> EOF >> > Oops there's a mistake there. Fixed: > > cat << EOF | ./qemu-system-i386 -display none -machine accel=qtest \ > -m 512M -machine pc -device floppy,unit=1,id=floppy0,drive=disk0 \ > -drive id=disk0,file=null-co://,file.read-zeroes=on,if=none,format=raw \ > -qtest stdio > outw 0x3f4 0x2500 > outb 0x3f5 0x81 > outb 0x3f5 0x0 > outb 0x3f5 0x0 > outb 0x3f5 0x0 > outw 0x3f2 0x14 > outw 0x3f4 0x0 > outw 0x3f4 0x4000 > outw 0x3f4 0x13 > outb 0x3f5 0x1 > outw 0x3f2 0x1405 > outw 0x3f4 0x0 > EOF > >> -Alex >> This actually still triggers after I apply this patch. It's not the same bug, or the patch isn't sufficient to address this bug. --js