Fix UDP header pointer after pskb_trim_rcsum()

[UDP]: Reread uh pointer after pskb_trim

The header may have moved when trimming.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index cfff930f2bafc78039908c1ab728d2340e4dc26d..f8068b06a26122356bbbd8363904bb23df1077ed 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1214,6 +1214,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
 
                if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
                        goto short_packet;
+               uh = skb->h.uh;
 
                udp4_csum_init(skb, uh);