4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Willem de Bruijn <will...@google.com>
[ Upstream commit 39b2dd765e0711e1efd1d1df089473a8dd93ad48 ]
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 <njaga...@cloudmark.com>
Signed-off-by: Willem de Bruijn <will...@google.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
net/ipv4/ip_sockglue.c | 2 +-
net/ipv6/datagram.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -137,7 +137,7 @@ static void ip_cmsg_recv_dstaddr(struct
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
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -700,7 +700,7 @@ void ip6_datagram_recv_specific_ctl(stru
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.
