[NET]: Verify gso_type too in gso_segment
We don't want nasty Xen guests to pass a TCPv6 packet in with gso_type set
to TCPv4 or even UDP (or a packet that's both TCP and UDP).
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 8d15715..318d467 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1106,7 +1106,15 @@
int ihl;
int id;
- if (!pskb_may_pull(skb, sizeof(*iph)))
+ if (unlikely(skb_shinfo(skb)->gso_type &
+ ~(SKB_GSO_TCPV4 |
+ SKB_GSO_UDP |
+ SKB_GSO_DODGY |
+ SKB_GSO_TCP_ECN |
+ 0)))
+ goto out;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
goto out;
iph = skb->nh.iph;
@@ -1114,7 +1122,7 @@
if (ihl < sizeof(*iph))
goto out;
- if (!pskb_may_pull(skb, ihl))
+ if (unlikely(!pskb_may_pull(skb, ihl)))
goto out;
skb->h.raw = __skb_pull(skb, ihl);
@@ -1125,7 +1133,7 @@
rcu_read_lock();
ops = rcu_dereference(inet_protos[proto]);
- if (ops && ops->gso_segment)
+ if (likely(ops && ops->gso_segment))
segs = ops->gso_segment(skb, features);
rcu_read_unlock();
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8044587..f6a2d92 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2170,8 +2170,19 @@
if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
/* Packet is from an untrusted source, reset gso_segs. */
- int mss = skb_shinfo(skb)->gso_size;
+ int type = skb_shinfo(skb)->gso_type;
+ int mss;
+ if (unlikely(type &
+ ~(SKB_GSO_TCPV4 |
+ SKB_GSO_DODGY |
+ SKB_GSO_TCP_ECN |
+ SKB_GSO_TCPV6 |
+ 0) ||
+ !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
+ goto out;
+
+ mss = skb_shinfo(skb)->gso_size;
skb_shinfo(skb)->gso_segs = (skb->len + mss - 1) / mss;
segs = NULL;