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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 90EE7C433E0 for ; Tue, 16 Jun 2020 16:14:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77A13208D5 for ; Tue, 16 Jun 2020 16:14:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592324065; bh=s4jSCyrUMmdQJIoeCOcOl+KOd/yopV34FZ0iqG0c5/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YmM/BNyHpqn59Xt1BS1JEZzD/vblbSHvHDCc9ZkQwqzKCNpPRy+OPkN74RBNfQ/cT q8qCkoAww1HqZudcV2x3AH9k8s31qGE21abuBtmH8JkdBtqS2augCYiHuZ+KFBfK4T TMxPSWWbSJf0hG05G6bhNlo+UfGF+oZoJerMZrn0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729881AbgFPPmo (ORCPT ); Tue, 16 Jun 2020 11:42:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:59612 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730941AbgFPPmm (ORCPT ); Tue, 16 Jun 2020 11:42:42 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9B57B208D5; Tue, 16 Jun 2020 15:42:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592322162; bh=s4jSCyrUMmdQJIoeCOcOl+KOd/yopV34FZ0iqG0c5/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DMRoCtRVdczc7W3qfOLMfCpwfzHkUagw/93iUPiEu8LYzOfgLliVqthuIcwUnfOkJ 7l2+IwhIMj4RvazXqJnzmfZOUmH9Pvg7AcjkW0m283yS6UdVO+RszXZI/Ucza2sUsd 95V0tlP0e9mfFB9eUCK46uWsrbwPgVd3fxyVH0Q8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ido Schimmel , Nikolay Aleksandrov , "David S. Miller" Subject: [PATCH 5.7 006/163] vxlan: Avoid infinite loop when suppressing NS messages with invalid options Date: Tue, 16 Jun 2020 17:33:00 +0200 Message-Id: <20200616153107.168487187@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200616153106.849127260@linuxfoundation.org> References: <20200616153106.849127260@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ido Schimmel [ Upstream commit 8066e6b449e050675df48e7c4b16c29f00507ff0 ] When proxy mode is enabled the vxlan device might reply to Neighbor Solicitation (NS) messages on behalf of remote hosts. In case the NS message includes the "Source link-layer address" option [1], the vxlan device will use the specified address as the link-layer destination address in its reply. To avoid an infinite loop, break out of the options parsing loop when encountering an option with length zero and disregard the NS message. This is consistent with the IPv6 ndisc code and RFC 4886 which states that "Nodes MUST silently discard an ND packet that contains an option with length zero" [2]. [1] https://tools.ietf.org/html/rfc4861#section-4.3 [2] https://tools.ietf.org/html/rfc4861#section-4.6 Fixes: 4b29dba9c085 ("vxlan: fix nonfunctional neigh_reduce()") Signed-off-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/vxlan.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1924,6 +1924,10 @@ static struct sk_buff *vxlan_na_create(s ns_olen = request->len - skb_network_offset(request) - sizeof(struct ipv6hdr) - sizeof(*ns); for (i = 0; i < ns_olen-1; i += (ns->opt[i+1]<<3)) { + if (!ns->opt[i + 1]) { + kfree_skb(reply); + return NULL; + } if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) { daddr = ns->opt + i + sizeof(struct nd_opt_hdr); break;