[UDP]: Make udp_encap_rcv use pskb_may_pull

[linux-2.6-omap-h63xx.git] / net / ipv4 / udp.c

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 865d75214a9ab1d741f3d8351359e95a0d8394e7..9e1bd374875e2f86f96dcb2f768849f20ed67c52 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -928,23 +928,32 @@ static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
        return 1; 
 #else
        struct udp_sock *up = udp_sk(sk);
-       struct udphdr *uh = skb->h.uh;
+       struct udphdr *uh;
        struct iphdr *iph;
        int iphlen, len;
   
-       __u8 *udpdata = (__u8 *)uh + sizeof(struct udphdr);
-       __be32 *udpdata32 = (__be32 *)udpdata;
+       __u8 *udpdata;
+       __be32 *udpdata32;
        __u16 encap_type = up->encap_type;
 
        /* if we're overly short, let UDP handle it */
-       if (udpdata > skb->tail)
+       len = skb->len - sizeof(struct udphdr);
+       if (len <= 0)
                return 1;
 
        /* if this is not encapsulated socket, then just return now */
        if (!encap_type)
                return 1;
 
-       len = skb->tail - udpdata;
+       /* If this is a paged skb, make sure we pull up
+        * whatever data we need to look at. */
+       if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
+               return 1;
+
+       /* Now we can get the pointers */
+       uh = skb->h.uh;
+       udpdata = (__u8 *)uh + sizeof(struct udphdr);
+       udpdata32 = (__be32 *)udpdata;
 
        switch (encap_type) {
        default: