From patchwork Mon Jan 25 22:24:48 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Xu X-Patchwork-Id: 8116841 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E20CBBEEE5 for ; Mon, 25 Jan 2016 23:08:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5644120389 for ; Mon, 25 Jan 2016 23:08:53 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A720F20260 for ; Mon, 25 Jan 2016 23:08:52 +0000 (UTC) Received: from localhost ([::1]:41222 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNqFg-0003tA-19 for patchwork-qemu-devel@patchwork.kernel.org; Mon, 25 Jan 2016 18:08:52 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34707) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNpaT-0003nb-JZ for qemu-devel@nongnu.org; Mon, 25 Jan 2016 17:26:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aNpaP-0008KZ-JH for qemu-devel@nongnu.org; Mon, 25 Jan 2016 17:26:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43073) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNpaP-0008KV-Df for qemu-devel@nongnu.org; Mon, 25 Jan 2016 17:26:13 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 1CD2F8F865 for ; Mon, 25 Jan 2016 22:26:13 +0000 (UTC) Received: from wei-thinkpad.nay.redhat.com (vpn1-5-80.pek2.redhat.com [10.72.5.80]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u0PMOxvu001754; Mon, 25 Jan 2016 17:26:05 -0500 From: wexu@redhat.com To: qemu-devel@nongnu.org Date: Tue, 26 Jan 2016 06:24:48 +0800 Message-Id: <1453760690-21221-9-git-send-email-wexu@redhat.com> In-Reply-To: <1453760690-21221-1-git-send-email-wexu@redhat.com> References: <1453760690-21221-1-git-send-email-wexu@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 X-Mailman-Approved-At: Mon, 25 Jan 2016 18:03:51 -0500 Cc: victork@redhat.com, mst@redhat.com, jasowang@redhat.com, yvugenfi@redhat.com, Wei Xu , marcel@redhat.com, dfleytma@redhat.com Subject: [Qemu-devel] [RFC Patch 08/10] Sanity check & More bypass cases check. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 1. IP options & IP fragment should be bypassed. 2. Sanity size check to prevent buffer overflow attack. Signed-off-by: Wei Xu --- hw/net/virtio-net.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 042b538..55e8e99 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1948,6 +1948,46 @@ static size_t virtio_net_rsc_drain_one(NetRscChain *chain, NetClientState *nc, return virtio_net_do_receive(nc, buf, size); } + +static int32_t virtio_net_rsc_filter4(NetRscChain *chain, struct ip_header *ip, + const uint8_t *buf, size_t size) +{ + uint16_t ip_len; + + if (size < (TCP4_OFFSET + sizeof(tcp_header))) { + return RSC_BYPASS; + } + + /* Not an ipv4 one */ + if (0x4 != ((0xF0 & ip->ip_ver_len) >> 4)) { + return RSC_BYPASS; + } + + /* Don't handle packets with ip option */ + if (5 != (0xF & ip->ip_ver_len)) { + return RSC_BYPASS; + } + + /* Don't handle packets with ip fragment */ + if (!(htons(ip->ip_off) & IP_DF)) { + return RSC_BYPASS; + } + + if (ip->ip_p != IPPROTO_TCP) { + return RSC_BYPASS; + } + + /* Sanity check */ + ip_len = htons(ip->ip_len); + if (ip_len < (sizeof(struct ip_header) + sizeof(struct tcp_header)) + || ip_len > (size - IP_OFFSET)) { + return RSC_BYPASS; + } + + return RSC_WANT; +} + + static size_t virtio_net_rsc_receive4(void *opq, NetClientState* nc, const uint8_t *buf, size_t size) { @@ -1958,6 +1998,10 @@ static size_t virtio_net_rsc_receive4(void *opq, NetClientState* nc, chain = (NetRscChain *)opq; ip = (struct ip_header *)(buf + IP_OFFSET); + if (RSC_WANT != virtio_net_rsc_filter4(chain, ip, buf, size)) { + return virtio_net_do_receive(nc, buf, size); + } + ret = virtio_net_rsc_parse_tcp_ctrl((uint8_t *)ip, (0xF & ip->ip_ver_len) << 2); if (RSC_BYPASS == ret) {