From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Yongjun Subject: [PATCH 2/2] xfrm6: fix the proto and ports decode of sctp protocol Date: Fri, 03 Jul 2009 10:59:49 +0800 Message-ID: <4A4D7425.7080005@cn.fujitsu.com> References: <4A4D7393.1060303@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 7bit Cc: Netdev To: Herbert Xu , David Miller Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:51590 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754248AbZGCDAl (ORCPT ); Thu, 2 Jul 2009 23:00:41 -0400 In-Reply-To: <4A4D7393.1060303@cn.fujitsu.com> Sender: netdev-owner@vger.kernel.org List-ID: The SCTP pushed the skb above the sctp chunk header, so the check of pskb_may_pull(skb, nh + offset + 1 - skb->data) in _decode_session6() will never return 0 and the ports decode of sctp will always fail. (nh + offset + 1 - skb->data < 0) Signed-off-by: Wei Yongjun --- net/ipv6/xfrm6_policy.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c index b4b16a4..3a3c677 100644 --- a/net/ipv6/xfrm6_policy.c +++ b/net/ipv6/xfrm6_policy.c @@ -157,7 +157,8 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr); ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr); - while (pskb_may_pull(skb, nh + offset + 1 - skb->data)) { + while (nh + offset + 1 < skb->data || + pskb_may_pull(skb, nh + offset + 1 - skb->data)) { nh = skb_network_header(skb); exthdr = (struct ipv6_opt_hdr *)(nh + offset); @@ -177,7 +178,8 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) case IPPROTO_TCP: case IPPROTO_SCTP: case IPPROTO_DCCP: - if (!onlyproto && pskb_may_pull(skb, nh + offset + 4 - skb->data)) { + if (!onlyproto && (nh + offset + 4 < skb->data || + pskb_may_pull(skb, nh + offset + 4 - skb->data))) { __be16 *ports = (__be16 *)exthdr; fl->fl_ip_sport = ports[!!reverse]; -- 1.6.2.2