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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 E149BC76194 for ; Thu, 25 Jul 2019 11:37:37 +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 B8AF422BF5 for ; Thu, 25 Jul 2019 11:37:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8AF422BF5 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]:58866 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqc40-0003vf-B0 for qemu-devel@archiver.kernel.org; Thu, 25 Jul 2019 07:37:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51194) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hqc3H-0000zB-4B for qemu-devel@nongnu.org; Thu, 25 Jul 2019 07:36:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hqc3G-00035Q-28 for qemu-devel@nongnu.org; Thu, 25 Jul 2019 07:36:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59946) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hqc3F-00035A-TJ; Thu, 25 Jul 2019 07:36:50 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4000F308339B; Thu, 25 Jul 2019 11:36:49 +0000 (UTC) Received: from t460s.redhat.com (ovpn-117-70.ams2.redhat.com [10.36.117.70]) by smtp.corp.redhat.com (Postfix) with ESMTP id B86D75D71C; Thu, 25 Jul 2019 11:36:47 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Thu, 25 Jul 2019 13:36:32 +0200 Message-Id: <20190725113638.4702-2-david@redhat.com> In-Reply-To: <20190725113638.4702-1-david@redhat.com> References: <20190725113638.4702-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Thu, 25 Jul 2019 11:36:49 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH-for-4.1 v4 1/7] virtio-balloon: Fix wrong sign extension of PFNs 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-stable@nongnu.org, Stefan Hajnoczi , Igor Mammedov , David Gibson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" If we directly cast from int to uint64_t, we will first sign-extend to an int64_t, which is wrong. We actually want to treat the PFNs like unsigned values. As far as I can see, this dates back to the initial virtio-balloon commit, but wasn't triggered as fairly big guests would be required. Cc: qemu-stable@nongnu.org Reported-by: Michael S. Tsirkin Reviewed-by: David Gibson Signed-off-by: David Hildenbrand --- hw/virtio/virtio-balloon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index e85d1c0d5c..515abf6553 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -343,8 +343,8 @@ static void virtio_balloon_handle_output(VirtIODevice= *vdev, VirtQueue *vq) } =20 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) = =3D=3D 4) { + unsigned int p =3D virtio_ldl_p(vdev, &pfn); hwaddr pa; - int p =3D virtio_ldl_p(vdev, &pfn); =20 pa =3D (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT; offset +=3D 4; --=20 2.21.0