xfrm4: fix the ports decode of sctp protocol

The SCTP pushed the skb data above the sctp chunk header, so the check
of pskb_may_pull(skb, xprth + 4 - skb->data) in _decode_session4() will
never return 0 because xprth + 4 - skb->data < 0, the ports decode of
sctp will always fail.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Yongjun 2009-07-02 16:57:23 +00:00 committed by David S. Miller
parent 15da4b1612
commit c615c9f3f3

View File

@ -136,7 +136,8 @@ _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
case IPPROTO_TCP:
case IPPROTO_SCTP:
case IPPROTO_DCCP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
if (xprth + 4 < skb->data ||
pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be16 *ports = (__be16 *)xprth;
fl->fl_ip_sport = ports[!!reverse];