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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98BAAC433EF for ; Wed, 13 Oct 2021 09:43:54 +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 2D40360F21 for ; Wed, 13 Oct 2021 09:43:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 2D40360F21 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:32862 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1maanh-000885-2T for qemu-devel@archiver.kernel.org; Wed, 13 Oct 2021 05:43:53 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:32934) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1maaku-0002xd-TN for qemu-devel@nongnu.org; Wed, 13 Oct 2021 05:41:02 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:53591) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1maakt-0003sQ-4Q for qemu-devel@nongnu.org; Wed, 13 Oct 2021 05:41:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634118058; 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=ihr5bWXnlFJsrh/1Gezdoj/2jjuw9hySv2u/G/IwRDI=; b=bUBCAn2C4pevpq7TYVeVrRqEuwdM4mOV2P+4kO511SQ4tUXc5q5iyZXU9kBQAxFh4hyqz/ C261hvFpa32aypQqv8X6PeOg88ipyrOgB2e9cQ4Prh0ruPdITRnHkPAmwi67p+mPPG65pN jS7kEcY7UmKt9YhkYIAlsLncOknis6I= 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-542-bdF_X08fMzOhb9FBrlyovQ-1; Wed, 13 Oct 2021 05:40:56 -0400 X-MC-Unique: bdF_X08fMzOhb9FBrlyovQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C78948BD960; Wed, 13 Oct 2021 09:40:55 +0000 (UTC) Received: from localhost (unknown [10.39.193.214]) by smtp.corp.redhat.com (Postfix) with ESMTP id 325F45C3DF; Wed, 13 Oct 2021 09:40:47 +0000 (UTC) Date: Wed, 13 Oct 2021 10:40:46 +0100 From: Stefan Hajnoczi To: Raphael Norwitz Subject: Re: [PATCH v1] libvhost-user: fix VHOST_USER_REM_MEM_REG skipping mmap_addr Message-ID: References: <20211011201047.62587-1-david@redhat.com> MIME-Version: 1.0 In-Reply-To: <20211011201047.62587-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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="0cyQIy4pqd7jfpIZ" Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.049, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-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: "Michael S . Tsirkin" , David Hildenbrand , qemu-devel@nongnu.org, Coiby Xu , qemu-stable@nongnu.org, Paolo Bonzini , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --0cyQIy4pqd7jfpIZ Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Oct 11, 2021 at 10:10:47PM +0200, David Hildenbrand wrote: > We end up not copying the mmap_addr of all existing regions, resulting > in a SEGFAULT once we actually try to map/access anything within our > memory regions. >=20 > Fixes: 875b9fd97b34 ("Support individual region unmap in libvhost-user") > Cc: qemu-stable@nongnu.org > Cc: Michael S. Tsirkin > Cc: Raphael Norwitz > Cc: "Marc-Andr=E9 Lureau" > Cc: Stefan Hajnoczi > Cc: Paolo Bonzini > Cc: Coiby Xu > Signed-off-by: David Hildenbrand > --- > subprojects/libvhost-user/libvhost-user.c | 1 + > 1 file changed, 1 insertion(+) >=20 > diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libv= host-user/libvhost-user.c > index bf09693255..787f4d2d4f 100644 > --- a/subprojects/libvhost-user/libvhost-user.c > +++ b/subprojects/libvhost-user/libvhost-user.c > @@ -816,6 +816,7 @@ vu_rem_mem_reg(VuDev *dev, VhostUserMsg *vmsg) { > shadow_regions[j].gpa =3D dev->regions[i].gpa; > shadow_regions[j].size =3D dev->regions[i].size; > shadow_regions[j].qva =3D dev->regions[i].qva; > + shadow_regions[j].mmap_addr =3D dev->regions[i].mmap_addr; > shadow_regions[j].mmap_offset =3D dev->regions[i].mmap_offse= t; > j++; > } else { Raphael: Some questions about vu_rem_mem_reg(): - What ensures that shadow_regions[VHOST_USER_MAX_RAM_SLOTS] is large enough? The add_mem_reg/set_mem_table code doesn't seem to check whether there is enough space in dev->regions[] before adding regions. - What happens when the master populated dev->regions[] with multiple copies of the same region? dev->nregions is only decremented once and no longer accurately reflects the number of elements in dev->regions[]. libvhost-user must not trust the vhost-user master since vhost-user needs to provide process isolation. Please add input validation. 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