From patchwork Mon Apr 1 20:59:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 10880681 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 06E21922 for ; Mon, 1 Apr 2019 21:44:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E51E022F3E for ; Mon, 1 Apr 2019 21:44:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D88622856A; Mon, 1 Apr 2019 21:44:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6B24A22F3E for ; Mon, 1 Apr 2019 21:44:18 +0000 (UTC) Received: from localhost ([127.0.0.1]:48730 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hB4j3-00070M-If for patchwork-qemu-devel@patchwork.kernel.org; Mon, 01 Apr 2019 17:44:17 -0400 Received: from eggs.gnu.org ([209.51.188.92]:41315) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hB453-0001or-Au for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hB452-0003jH-1S for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:42132) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hB451-0003cw-KQ for qemu-devel@nongnu.org; Mon, 01 Apr 2019 17:02:55 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x31L1qkI122257 for ; Mon, 1 Apr 2019 17:02:44 -0400 Received: from e12.ny.us.ibm.com (e12.ny.us.ibm.com [129.33.205.202]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rksyg8s6f-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 01 Apr 2019 17:02:43 -0400 Received: from localhost by e12.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 1 Apr 2019 22:02:40 +0100 Received: from b01ledav001.gho.pok.ibm.com (b01ledav001.gho.pok.ibm.com [9.57.199.106]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x31L2djH23396492 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 1 Apr 2019 21:02:39 GMT Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 24BB32805A; Mon, 1 Apr 2019 21:02:39 +0000 (GMT) Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EDB6628058; Mon, 1 Apr 2019 21:02:38 +0000 (GMT) Received: from localhost (unknown [9.80.94.43]) by b01ledav001.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 1 Apr 2019 21:02:38 +0000 (GMT) From: Michael Roth To: qemu-devel@nongnu.org Date: Mon, 1 Apr 2019 15:59:35 -0500 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190401210011.16009-1-mdroth@linux.vnet.ibm.com> References: <20190401210011.16009-1-mdroth@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19040121-0060-0000-0000-000003271874 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010857; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000283; SDB=6.01182941; UDB=6.00619269; IPR=6.00963684; MB=3.00026249; MTD=3.00000008; XFM=3.00000015; UTC=2019-04-01 21:02:42 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19040121-0061-0000-0000-000048CD8411 Message-Id: <20190401210011.16009-62-mdroth@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-04-01_06:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904010136 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 61/97] net: drop too large packet early 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: Peter Maydell , Jason Wang , Li Qiang , qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Jason Wang We try to detect and drop too large packet (>INT_MAX) in 1592a9947036 ("net: ignore packet size greater than INT_MAX") during packet delivering. Unfortunately, this is not sufficient as we may hit another integer overflow when trying to queue such large packet in qemu_net_queue_append_iov(): - size of the allocation may overflow on 32bit - packet->size is integer which may overflow even on 64bit Fixing this by moving the check to qemu_sendv_packet_async() which is the entrance of all networking codes and reduce the limit to NET_BUFSIZE to be more conservative. This works since: - For the callers that call qemu_sendv_packet_async() directly, they only care about if zero is returned to determine whether to prevent the source from producing more packets. A callback will be triggered if peer can accept more then source could be enabled. This is usually used by high speed networking implementation like virtio-net or netmap. - For the callers that call qemu_sendv_packet() that calls qemu_sendv_packet_async() indirectly, they often ignore the return value. In this case qemu will just the drop packets if peer can't receive. Qemu will copy the packet if it was queued. So it was safe for both kinds of the callers to assume the packet was sent. Since we move the check from qemu_deliver_packet_iov() to qemu_sendv_packet_async(), it would be safer to make qemu_deliver_packet_iov() static to prevent any external user in the future. This is a revised patch of CVE-2018-17963. Cc: qemu-stable@nongnu.org Cc: Li Qiang Fixes: 1592a9947036 ("net: ignore packet size greater than INT_MAX") Reported-by: Li Qiang Reviewed-by: Li Qiang Signed-off-by: Jason Wang Reviewed-by: Thomas Huth Message-id: 20181204035347.6148-2-jasowang@redhat.com Signed-off-by: Peter Maydell (cherry picked from commit 25c01bd19d0e4b66f357618aeefda1ef7a41e21a) Signed-off-by: Michael Roth --- include/net/net.h | 6 ------ net/net.c | 28 +++++++++++++++++----------- 2 files changed, 17 insertions(+), 17 deletions(-) diff --git a/include/net/net.h b/include/net/net.h index 1425960f76..3e4638b8c6 100644 --- a/include/net/net.h +++ b/include/net/net.h @@ -169,12 +169,6 @@ void qemu_check_nic_model(NICInfo *nd, const char *model); int qemu_find_nic_model(NICInfo *nd, const char * const *models, const char *default_model); -ssize_t qemu_deliver_packet_iov(NetClientState *sender, - unsigned flags, - const struct iovec *iov, - int iovcnt, - void *opaque); - void print_net_client(Monitor *mon, NetClientState *nc); void hmp_info_network(Monitor *mon, const QDict *qdict); void net_socket_rs_init(SocketReadState *rs, diff --git a/net/net.c b/net/net.c index 46db72811b..f8275843fb 100644 --- a/net/net.c +++ b/net/net.c @@ -231,6 +231,11 @@ static void qemu_net_client_destructor(NetClientState *nc) { g_free(nc); } +static ssize_t qemu_deliver_packet_iov(NetClientState *sender, + unsigned flags, + const struct iovec *iov, + int iovcnt, + void *opaque); static void qemu_net_client_setup(NetClientState *nc, NetClientInfo *info, @@ -705,22 +710,18 @@ static ssize_t nc_sendv_compat(NetClientState *nc, const struct iovec *iov, return ret; } -ssize_t qemu_deliver_packet_iov(NetClientState *sender, - unsigned flags, - const struct iovec *iov, - int iovcnt, - void *opaque) +static ssize_t qemu_deliver_packet_iov(NetClientState *sender, + unsigned flags, + const struct iovec *iov, + int iovcnt, + void *opaque) { NetClientState *nc = opaque; - size_t size = iov_size(iov, iovcnt); int ret; - if (size > INT_MAX) { - return size; - } if (nc->link_down) { - return size; + return iov_size(iov, iovcnt); } if (nc->receive_disabled) { @@ -745,10 +746,15 @@ ssize_t qemu_sendv_packet_async(NetClientState *sender, NetPacketSent *sent_cb) { NetQueue *queue; + size_t size = iov_size(iov, iovcnt); int ret; + if (size > NET_BUFSIZE) { + return size; + } + if (sender->link_down || !sender->peer) { - return iov_size(iov, iovcnt); + return size; } /* Let filters handle the packet first */