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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 A6882C2D0E2 for ; Tue, 22 Sep 2020 08:01:09 +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 BD885239A1 for ; Tue, 22 Sep 2020 08:01:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OVim8s8Y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD885239A1 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]:33534 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kKdEZ-0006lG-6x for qemu-devel@archiver.kernel.org; Tue, 22 Sep 2020 04:01:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44032) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kKdD6-0006BS-BU for qemu-devel@nongnu.org; Tue, 22 Sep 2020 03:59:36 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:48254) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kKdD3-00038Q-8z for qemu-devel@nongnu.org; Tue, 22 Sep 2020 03:59:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600761572; 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: in-reply-to:in-reply-to:references:references; bh=0fQYLg2+p5zbjNiO5yL0pfajKcfknZCyyXTT1jnYqO0=; b=OVim8s8Y4yKuF4JCn9KKyhnhJ+GqMpEY99kHSuCy4KKVmL+Rlzd3k7bvHeB11g31b4Rvub G68GEbneAJtuHV1gyd2uv3i6aQnGU4WjqWLPW5eqpzfp9fvrzSmZpNZHXUE1T/jVfpkKxo 9WBQ8A8sKyhavxJm284BsMnGs24re3w= 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-238-pdo4IgcYOqa5BkTH3KJdUA-1; Tue, 22 Sep 2020 03:59:28 -0400 X-MC-Unique: pdo4IgcYOqa5BkTH3KJdUA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 541EF8030C7; Tue, 22 Sep 2020 07:59:27 +0000 (UTC) Received: from localhost (ovpn-112-243.ams2.redhat.com [10.36.112.243]) by smtp.corp.redhat.com (Postfix) with ESMTP id B2BB05DA30; Tue, 22 Sep 2020 07:59:23 +0000 (UTC) Date: Tue, 22 Sep 2020 08:59:22 +0100 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: Re: [PATCH v2 0/3] virtio: restore elem->in/out_sg after iov_discard_front/back() Message-ID: <20200922075922.GA201611@stefanha-x1.localdomain> References: <20200917094455.822379-1-stefanha@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200917094455.822379-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="opJtzjQTFsWo+cga" Content-Disposition: inline Received-SPF: pass client-ip=63.128.21.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/22 02:07:04 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -35 X-Spam_score: -3.6 X-Spam_bar: --- X-Spam_report: (-3.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.455, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: Kevin Wolf , qemu-block@nongnu.org, "Michael S. Tsirkin" , Max Reitz , Alexander Bulekov , "Gonglei \(Arei\)" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --opJtzjQTFsWo+cga Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 17, 2020 at 10:44:52AM +0100, Stefan Hajnoczi wrote: > v2: > * Add missing undo in virtio-blk write zeroes error path [Li Qiang] >=20 > Both virtio-blk and virtio-crypto use destructive iov_discard_front/back(= ) > operations on elem->in/out_sg. virtqueue_push() calls dma_memory_unmap() = on the > modified iovec arrays. The memory addresses may not match those originall= y > mapped with dma_memory_map(). >=20 > This raises several issues: > 1. MemoryRegion references can be leaked. > 2. Dirty memory may not be tracked. > 3. The non-RAM bounce buffer can be leaked. >=20 > This patch series solves the issue in two ways: > 1. virtio-blk uses a new iov_discard_undo() API to restore iovec arrays. > 2. virtio-crypto uses g_memdup() to avoid modifying the original iovec ar= rays. >=20 > The g_memdup() approach is slower than iov_discard_undo() but less > complex/fragile. I am less familiar with the virtio-crypto code and it us= es > more complex sequences of iov_discard_front/back() calls than virtio-blk.= If > anyone feels like optimizing virtio-crypto, please go ahead. >=20 > The virtio-blk bug was found by Alexander Bulekov's fuzzing effort. I fou= nd the > virtio-crypto bug through code inspection. >=20 > Stefan Hajnoczi (3): > util/iov: add iov_discard_undo() > virtio-blk: undo destructive iov_discard_*() operations > virtio-crypto: don't modify elem->in/out_sg >=20 > include/hw/virtio/virtio-blk.h | 2 + > include/qemu/iov.h | 23 +++++ > hw/block/virtio-blk.c | 11 ++- > hw/virtio/virtio-crypto.c | 17 +++- > tests/test-iov.c | 165 +++++++++++++++++++++++++++++++++ > util/iov.c | 50 +++++++++- > 6 files changed, 259 insertions(+), 9 deletions(-) >=20 > --=20 > 2.26.2 >=20 Thanks, applied to my block tree: https://github.com/stefanha/qemu/commits/block Stefan --opJtzjQTFsWo+cga Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAl9prtoACgkQnKSrs4Gr c8hKDAf/RIWKzIAc/Tu6DQQcolRKyHr0ETFNkGepi+ABGLklu6+zi0u6K1oncrN6 hY03qWBWG1CP6WfnsNbKh7prr+9fQ3Nu0VwDAympBovrRN51x4JD0XzKb7pG93RN NPTp6XguIc0xwywhrnc885nxdTb9AKystd8F2mOFWjtYz7al8HwRyLEf/mANmIEz /jHtlt3l75rE7seKGr9B/wgpL7DU6+5RHPyzBmpjbiST2QV2OA/HaDiBYA7UuBXW jmbAMlKSS9xX3mvnAu3gaQA6XQyrF0rcBEkfeZqlfneRe2Kwkpfcr9PNtQTfn+TZ tIvRpQyqndZB4xYUvNqXNnbibjHI9A== =uAnT -----END PGP SIGNATURE----- --opJtzjQTFsWo+cga--