From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: [PATCH net] inet: fix IP(V6)_RECVORIGDSTADDR for udp sockets Date: Thu, 22 Dec 2016 18:19:16 -0500 Message-ID: <1482448756-83129-1-git-send-email-willemdebruijn.kernel@gmail.com> Cc: davem@davemloft.net, njagabar@cloudmark.com, samanthakumar@google.com, Willem de Bruijn To: netdev@vger.kernel.org Return-path: Received: from mail-qk0-f193.google.com ([209.85.220.193]:34746 "EHLO mail-qk0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941233AbcLVXTU (ORCPT ); Thu, 22 Dec 2016 18:19:20 -0500 Received: by mail-qk0-f193.google.com with SMTP id t184so15130474qkd.1 for ; Thu, 22 Dec 2016 15:19:19 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: From: Willem de Bruijn Socket cmsg IP(V6)_RECVORIGDSTADDR checks that port range lies within the packet. For sockets that have transport headers pulled, transport offset can be negative. Use signed comparison to avoid overflow. Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") Reported-by: Nisar Jagabar Signed-off-by: Willem de Bruijn --- net/ipv4/ip_sockglue.c | 2 +- net/ipv6/datagram.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 8b13881..9760734 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -148,7 +148,7 @@ static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb) const struct iphdr *iph = ip_hdr(skb); __be16 *ports = (__be16 *)skb_transport_header(skb); - if (skb_transport_offset(skb) + 4 > skb->len) + if (skb_transport_offset(skb) + 4 > (int)skb->len) return; /* All current transport protocols have the port numbers in the diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c index 0489e19..1407426 100644 --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -701,7 +701,7 @@ void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg, struct sockaddr_in6 sin6; __be16 *ports = (__be16 *) skb_transport_header(skb); - if (skb_transport_offset(skb) + 4 <= skb->len) { + if (skb_transport_offset(skb) + 4 <= (int)skb->len) { /* All current transport protocols have the port numbers in the * first four bytes of the transport header and this function is * written with this assumption in mind. -- 2.8.0.rc3.226.g39d4020