From c615c9f3f3cea60279b1bb38e8ef27bd575ecd0c Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Thu, 2 Jul 2009 16:57:23 +0000 Subject: [PATCH] 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 Acked-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/xfrm4_policy.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c index 60d918c96a4f..0071ee6f441f 100644 --- a/net/ipv4/xfrm4_policy.c +++ b/net/ipv4/xfrm4_policy.c @@ -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]; -- 2.20.1