From nobody Sat Nov 8 10:42:51 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (209.51.188.17 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1550119450899235.4300093163531; Wed, 13 Feb 2019 20:44:10 -0800 (PST) Received: from localhost ([127.0.0.1]:39981 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gu8sW-0004kF-Ow for importer@patchew.org; Wed, 13 Feb 2019 23:44:04 -0500 Received: from eggs.gnu.org ([209.51.188.92]:46008) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gu8p7-0002GB-3q for qemu-devel@nongnu.org; Wed, 13 Feb 2019 23:40:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gu8os-0006ye-Mq for qemu-devel@nongnu.org; Wed, 13 Feb 2019 23:40:26 -0500 Received: from ozlabs.org ([2401:3900:2:1::2]:45415) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gu8oh-0006OW-2y; Wed, 13 Feb 2019 23:40:09 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 440Nvr1xbXz9sMx; Thu, 14 Feb 2019 15:39:20 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1550119160; bh=3/yOpaPIHgovVGzYhgaTIRb3gPBnbEomTVCzz6dAsNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SjOrX1a4yAVLz5ZbgC+0+PNWx1ia96g6ikaz5SECMW9AdT7YJSOO0J+Hk9F3TiaXJ rqsP8zDJlNHZ3Sm9yimq8boNe8EE6M3KP5/qXPHmLILfvGdo6SbdaejguOVj65Az5F pxUC0DlqsQaK7PVVwwP1gJFT2u6lxK8VSJnkIiRY= From: David Gibson To: mst@redhat.com, qemu-devel@nongnu.org Date: Thu, 14 Feb 2019 15:39:13 +1100 Message-Id: <20190214043916.22128-3-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190214043916.22128-1-david@gibson.dropbear.id.au> References: <20190214043916.22128-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2401:3900:2:1::2 Subject: [Qemu-devel] [PATCH 2/5] virtio-balloon: Corrections to address verification X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Hildenbrand , qemu-ppc@nongnu.org, David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" The virtio-balloon device's verification of the address given to it by the guest has a number of faults: * The addresses here are guest physical addresses, which should be 'hwaddr' rather than 'ram_addr_t' (the distinction is admittedly pretty subtle and confusing) * We don't check for section.mr being NULL, which is the main way that memory_region_find() reports basic failures. We really need to check that before looking at any other section fields, because memory_region_find() doesn't initialize them on the failure path * We're passing a length of '1' to memory_region_find(), but really the guest is requesting that we put the entire page into the balloon, so it makes more sense to call it with BALLOON_PAGE_SIZE Signed-off-by: David Gibson Reviewed-by: David Hildenbrand Reviewed-by: Michael S. Tsirkin Reviewed-by: Greg Kurz --- hw/virtio/virtio-balloon.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 43af521884..eb357824d8 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -221,17 +221,20 @@ 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) { - ram_addr_t pa; - ram_addr_t addr; + hwaddr pa; + hwaddr addr; int p =3D virtio_ldl_p(vdev, &pfn); =20 - pa =3D (ram_addr_t) p << VIRTIO_BALLOON_PFN_SHIFT; + pa =3D (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT; offset +=3D 4; =20 - /* FIXME: remove get_system_memory(), but how? */ - section =3D memory_region_find(get_system_memory(), pa, 1); - if (!int128_nz(section.size) || - !memory_region_is_ram(section.mr) || + section =3D memory_region_find(get_system_memory(), pa, + BALLOON_PAGE_SIZE); + if (!section.mr) { + trace_virtio_balloon_bad_addr(pa); + continue; + } + if (!memory_region_is_ram(section.mr) || memory_region_is_rom(section.mr) || memory_region_is_romd(section.mr)) { trace_virtio_balloon_bad_addr(pa); --=20 2.20.1