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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 12E2CC433DF for ; Mon, 27 Jul 2020 09:54:21 +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 D23472075D for ; Mon, 27 Jul 2020 09:54:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="St/jgGLr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D23472075D 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]:42024 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jzzps-0003Lj-5w for qemu-devel@archiver.kernel.org; Mon, 27 Jul 2020 05:54:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40524) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jzzp8-0002ej-0E for qemu-devel@nongnu.org; Mon, 27 Jul 2020 05:53:34 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:60564 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jzzp6-0006uP-FS for qemu-devel@nongnu.org; Mon, 27 Jul 2020 05:53:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595843611; 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=HJ6bXqJqnQvjdEfe/zSrkOmWsXEi8NFyhUfcd1eB9wk=; b=St/jgGLrRsLk6ImfKSyq/QghE5y00aEojJWc/4LZ3oXNyaug3U4QkDKU8SZSF/qfc0gQSJ 4gfXFhUnSpMsEJb7SRV1hqX+6PJWPdYcBQQFUBvU934VLXwLDRDu5sV15QiTLB/hb7mCHS O912H9jteRea8/X7bt6u1xqre3ONTMU= 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-279-8C7O55SgOc2kie3GIG_AvQ-1; Mon, 27 Jul 2020 05:53:29 -0400 X-MC-Unique: 8C7O55SgOc2kie3GIG_AvQ-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 E8DD21005504 for ; Mon, 27 Jul 2020 09:53:28 +0000 (UTC) Received: from gondolin (ovpn-112-210.ams2.redhat.com [10.36.112.210]) by smtp.corp.redhat.com (Postfix) with ESMTP id E7CC560C87; Mon, 27 Jul 2020 09:53:24 +0000 (UTC) Date: Mon, 27 Jul 2020 11:53:22 +0200 From: Cornelia Huck To: "Michael S. Tsirkin" Subject: Re: [PATCH] virtio-net: check the existence of peer before accesing its config Message-ID: <20200727115322.4e7fe1aa.cohuck@redhat.com> In-Reply-To: <20200727053954-mutt-send-email-mst@kernel.org> References: <20200727074328.2279-1-jasowang@redhat.com> <20200727053954-mutt-send-email-mst@kernel.org> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=cohuck@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/27 00:16:29 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, 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: Jason Wang , qemu-devel@nongnu.org, Cindy Lu Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, 27 Jul 2020 05:41:17 -0400 "Michael S. Tsirkin" wrote: > On Mon, Jul 27, 2020 at 03:43:28PM +0800, Jason Wang wrote: > > We try to get config from peer unconditionally which may lead NULL > > pointer dereference. Add a check before trying to access the config. > > > > Fixes: 108a64818e69b ("vhost-vdpa: introduce vhost-vdpa backend") > > Cc: Cindy Lu > > Tested-by: Cornelia Huck > > Signed-off-by: Jason Wang > > I am a bit lost here. Isn't this invoked > when guest attempts to read the config? > With no peer, what do we return to guest? Same as with a non-vdpa peer? It's the dereference that needs to be guarded. > A code comment might be helpful here. > > > --- > > hw/net/virtio-net.c | 22 +++++++++++----------- > > 1 file changed, 11 insertions(+), 11 deletions(-)