From: Willem de Bruijn <will...@google.com> 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> --- 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