From patchwork Thu May 3 16:13:25 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Brivio X-Patchwork-Id: 908117 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=openvswitch.org (client-ip=140.211.169.12; helo=mail.linuxfoundation.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40cL0Z0SZNz9s37 for ; Fri, 4 May 2018 02:18:05 +1000 (AEST) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id A0042899; Thu, 3 May 2018 16:14:59 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 5503930 for ; Thu, 3 May 2018 16:14:58 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A57314FA for ; Thu, 3 May 2018 16:14:57 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8BFE6818F056; Thu, 3 May 2018 16:14:56 +0000 (UTC) Received: from epycfail.redhat.com (unknown [10.36.112.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 992F4111765B; Thu, 3 May 2018 16:14:54 +0000 (UTC) From: Stefano Brivio To: Pravin B Shelar , "David S. Miller" Date: Thu, 3 May 2018 18:13:25 +0200 Message-Id: <44f4cc7dd6ceb5aac6045e59ff49dce70dd53e74.1525363636.git.sbrivio@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Thu, 03 May 2018 16:14:56 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Thu, 03 May 2018 16:14:56 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'sbrivio@redhat.com' RCPT:'' X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: dev@openvswitch.org, netdev@vger.kernel.org, Jesse Gross , Hangbin Liu , Sabrina Dubroca Subject: [ovs-dev] [PATCH net] openvswitch: Don't swap table in nlattr_set() after OVS_ATTR_NESTED is found X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ovs-dev-bounces@openvswitch.org Errors-To: ovs-dev-bounces@openvswitch.org If an OVS_ATTR_NESTED attribute type is found while walking through netlink attributes, we call nlattr_set() recursively passing the length table for the following nested attributes, if different from the current one. However, once we're done with those sub-nested attributes, we should continue walking through attributes using the current table, instead of using the one related to the sub-nested attributes. For example, given this sequence: 1 OVS_KEY_ATTR_PRIORITY 2 OVS_KEY_ATTR_TUNNEL 3 OVS_TUNNEL_KEY_ATTR_ID 4 OVS_TUNNEL_KEY_ATTR_IPV4_SRC 5 OVS_TUNNEL_KEY_ATTR_IPV4_DST 6 OVS_TUNNEL_KEY_ATTR_TTL 7 OVS_TUNNEL_KEY_ATTR_TP_SRC 8 OVS_TUNNEL_KEY_ATTR_TP_DST 9 OVS_KEY_ATTR_IN_PORT 10 OVS_KEY_ATTR_SKB_MARK 11 OVS_KEY_ATTR_MPLS we switch to the 'ovs_tunnel_key_lens' table on attribute #3, and we don't switch back to 'ovs_key_lens' while setting attributes #9 to #11 in the sequence. As OVS_KEY_ATTR_MPLS evaluates to 21, and the array size of 'ovs_tunnel_key_lens' is 15, we also get this kind of KASan splat while accessing the wrong table: [ 7654.586496] ================================================================== [ 7654.594573] BUG: KASAN: global-out-of-bounds in nlattr_set+0x164/0xde9 [openvswitch] [ 7654.603214] Read of size 4 at addr ffffffffc169ecf0 by task handler29/87430 [ 7654.610983] [ 7654.612644] CPU: 21 PID: 87430 Comm: handler29 Kdump: loaded Not tainted 3.10.0-866.el7.test.x86_64 #1 [ 7654.623030] Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.1.7 06/16/2016 [ 7654.631379] Call Trace: [ 7654.634108] [] dump_stack+0x19/0x1b [ 7654.639843] [] print_address_description+0x33/0x290 [ 7654.647129] [] ? nlattr_set+0x164/0xde9 [openvswitch] [ 7654.654607] [] kasan_report.part.3+0x242/0x330 [ 7654.661406] [] __asan_report_load4_noabort+0x34/0x40 [ 7654.668789] [] nlattr_set+0x164/0xde9 [openvswitch] [ 7654.676076] [] ovs_nla_get_match+0x10c8/0x1900 [openvswitch] [ 7654.684234] [] ? genl_rcv+0x28/0x40 [ 7654.689968] [] ? netlink_unicast+0x3f3/0x590 [ 7654.696574] [] ? ovs_nla_put_tunnel_info+0xb0/0xb0 [openvswitch] [ 7654.705122] [] ? unwind_get_return_address+0xb0/0xb0 [ 7654.712503] [] ? system_call_fastpath+0x1c/0x21 [ 7654.719401] [] ? update_stack_state+0x229/0x370 [ 7654.726298] [] ? update_stack_state+0x229/0x370 [ 7654.733195] [] ? kasan_unpoison_shadow+0x35/0x50 [ 7654.740187] [] ? kasan_kmalloc+0xaa/0xe0 [ 7654.746406] [] ? kasan_slab_alloc+0x12/0x20 [ 7654.752914] [] ? memset+0x31/0x40 [ 7654.758456] [] ovs_flow_cmd_new+0x2b2/0xf00 [openvswitch] [snip] [ 7655.132484] The buggy address belongs to the variable: [ 7655.138226] ovs_tunnel_key_lens+0xf0/0xffffffffffffd400 [openvswitch] [ 7655.145507] [ 7655.147166] Memory state around the buggy address: [ 7655.152514] ffffffffc169eb80: 00 00 00 00 00 00 00 00 00 00 fa fa fa fa fa fa [ 7655.160585] ffffffffc169ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 7655.168644] >ffffffffc169ec80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fa fa [ 7655.176701] ^ [ 7655.184372] ffffffffc169ed00: fa fa fa fa 00 00 00 00 fa fa fa fa 00 00 00 05 [ 7655.192431] ffffffffc169ed80: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00 [ 7655.200490] ================================================================== Reported-by: Hangbin Liu Fixes: 982b52700482 ("openvswitch: Fix mask generation for nested attributes.") Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca --- net/openvswitch/flow_netlink.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c index 7322aa1e382e..492ab0c36f7c 100644 --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -1712,13 +1712,10 @@ static void nlattr_set(struct nlattr *attr, u8 val, /* The nlattr stream should already have been validated */ nla_for_each_nested(nla, attr, rem) { - if (tbl[nla_type(nla)].len == OVS_ATTR_NESTED) { - if (tbl[nla_type(nla)].next) - tbl = tbl[nla_type(nla)].next; - nlattr_set(nla, val, tbl); - } else { + if (tbl[nla_type(nla)].len == OVS_ATTR_NESTED) + nlattr_set(nla, val, tbl[nla_type(nla)].next ? : tbl); + else memset(nla_data(nla), val, nla_len(nla)); - } if (nla_type(nla) == OVS_KEY_ATTR_CT_STATE) *(u32 *)nla_data(nla) &= CT_SUPPORTED_MASK;