Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932127AbcDRCgy (ORCPT ); Sun, 17 Apr 2016 22:36:54 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36520 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754449AbcDRCgv (ORCPT ); Sun, 17 Apr 2016 22:36:51 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bill Sommerfeld , "David S. Miller" Subject: [PATCH 4.4 040/137] udp6: fix UDP/IPv6 encap resubmit path Date: Mon, 18 Apr 2016 11:28:22 +0900 Message-Id: <20160418022509.891533270@linuxfoundation.org> X-Mailer: git-send-email 2.8.0 In-Reply-To: <20160418022507.236379264@linuxfoundation.org> References: <20160418022507.236379264@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1416 Lines: 43 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bill Sommerfeld [ Upstream commit 59dca1d8a6725a121dae6c452de0b2611d5865dc ] IPv4 interprets a negative return value from a protocol handler as a request to redispatch to a new protocol. In contrast, IPv6 interprets a negative value as an error, and interprets a positive value as a request for redispatch. UDP for IPv6 was unaware of this difference. Change __udp6_lib_rcv() to return a positive value for redispatch. Note that the socket's encap_rcv hook still needs to return a negative value to request dispatch, and in the case of IPv6 packets, adjust IP6CB(skb)->nhoff to identify the byte containing the next protocol. Signed-off-by: Bill Sommerfeld Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/udp.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -916,11 +916,9 @@ int __udp6_lib_rcv(struct sk_buff *skb, ret = udpv6_queue_rcv_skb(sk, skb); sock_put(sk); - /* a return value > 0 means to resubmit the input, but - * it wants the return to be -protocol, or 0 - */ + /* a return value > 0 means to resubmit the input */ if (ret > 0) - return -ret; + return ret; return 0; }