From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:57216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730594AbeKIHiI (ORCPT ); Fri, 9 Nov 2018 02:38:08 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefano Brivio , Sabrina Dubroca , "David S. Miller" Subject: [PATCH 4.4 091/114] ipv6/ndisc: Preserve IPv6 control buffer if protocol error handlers are called Date: Thu, 8 Nov 2018 13:51:46 -0800 Message-Id: <20181108215109.010136833@linuxfoundation.org> In-Reply-To: <20181108215059.051093652@linuxfoundation.org> References: <20181108215059.051093652@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefano Brivio [ Upstream commit ee1abcf689353f36d9322231b4320926096bdee0 ] Commit a61bbcf28a8c ("[NET]: Store skb->timestamp as offset to a base timestamp") introduces a neighbour control buffer and zeroes it out in ndisc_rcv(), as ndisc_recv_ns() uses it. Commit f2776ff04722 ("[IPV6]: Fix address/interface handling in UDP and DCCP, according to the scoping architecture.") introduces the usage of the IPv6 control buffer in protocol error handlers (e.g. inet6_iif() in present-day __udp6_lib_err()). Now, with commit b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect()."), we call protocol error handlers from ndisc_redirect_rcv(), after the control buffer is already stolen and some parts are already zeroed out. This implies that inet6_iif() on this path will always return zero. This gives unexpected results on UDP socket lookup in __udp6_lib_err(), as we might actually need to match sockets for a given interface. Instead of always claiming the control buffer in ndisc_rcv(), do that only when needed. Fixes: b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect().") Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ndisc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1649,10 +1649,9 @@ int ndisc_rcv(struct sk_buff *skb) return 0; } - memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); - switch (msg->icmph.icmp6_type) { case NDISC_NEIGHBOUR_SOLICITATION: + memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); ndisc_recv_ns(skb); break;