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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 92BEAC433E0 for ; Mon, 8 Jun 2020 23:40:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6834E2068D for ; Mon, 8 Jun 2020 23:40:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591659658; bh=YOvx+5mj0Dgp9Ng7is8QTXRd5/0609AkYbrMTO5lq0o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wlcE7d5THk0gN7dRtmez0SMTLpr1pxqW+1vsU/xxi+g6dFQ/tDxPUrQKQzzY3IbbZ t3lq4juOcSQp9mF2RKQp6hG/9hPDmrGZAJilGbXrn6y+enpx6gXCr9LxHfU8pie6oY G/fL5OAgwvTVeIXE2C9bvMYlZhDzTgsqZL3OIFFo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731853AbgFHX1w (ORCPT ); Mon, 8 Jun 2020 19:27:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:56592 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732171AbgFHX1u (ORCPT ); Mon, 8 Jun 2020 19:27:50 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6E0FA20801; Mon, 8 Jun 2020 23:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658869; bh=YOvx+5mj0Dgp9Ng7is8QTXRd5/0609AkYbrMTO5lq0o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xQA6drIu2iTxyDeoHXgbVusq3oa+ht7aoknx7PHPIB22VYvXnw5ahbW1zogQjDVuU iiUWbCbJiNrPHNQoBQWoSHOBCkxmvB/uhTDqe4w2DPyANyzqv31mFKR/W5UhIBbCom PM3f+/IzHkJwPVXUbz+u3jUMM7hQNnFo754UXrfQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ido Schimmel , Nikolay Aleksandrov , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 50/50] vxlan: Avoid infinite loop when suppressing NS messages with invalid options Date: Mon, 8 Jun 2020 19:26:40 -0400 Message-Id: <20200608232640.3370262-50-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608232640.3370262-1-sashal@kernel.org> References: <20200608232640.3370262-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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: Sasha Levin --- drivers/net/vxlan.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 58ddb6c90418..b1470d30d079 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1521,6 +1521,10 @@ static struct sk_buff *vxlan_na_create(struct sk_buff *request, daddr = eth_hdr(request)->h_source; ns_olen = request->len - skb_transport_offset(request) - 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; -- 2.25.1