releases/2.6.16.10/ipv6-xfrm-fix-decoding-session-with-preceding-extension-header.patch

From stable-bounces@linux.kernel.org Tue Apr 18 19:12:27 2006
Date: Wed, 19 Apr 2006 11:14:23 +0900 (JST)
Message-Id: <20060419.111423.48104035.yoshfuji@linux-ipv6.org>
To: stable@kernel.org
From: YOSHIFUJI Hideaki / =?iso-2022-jp?B?GyRCNUhGIzFRTEAbKEI=?=
	<yoshfuji@linux-ipv6.org>
Cc: netdev-core@vger.kernel.org, yoshfuji@linux-ipv6.org,
        kazunori@miyazawa.org, takamiya@po.ntts.co.jp
Subject: IPV6: XFRM: Fix decoding session with preceding extension header(s).

[IPV6] XFRM: Fix decoding session with preceding extension header(s).

We did not correctly decode session with preceding extension
header(s).  This was because we had already pulled preceding
headers, skb->nh.raw + 40 + 1 - skb->data was minus, and
pskb_may_pull() failed.

We now have IP6CB(skb)->nhoff and skb->h.raw, and we can
start parsing / decoding upper layer protocol from current
position.

Tracked down by Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
and tested by Kazunori Miyazawa <kazunori@miyazawa.org>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 net/ipv6/xfrm6_policy.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- linux-2.6.16.9.orig/net/ipv6/xfrm6_policy.c
+++ linux-2.6.16.9/net/ipv6/xfrm6_policy.c
@@ -191,10 +191,10 @@ error:
 static inline void
 _decode_session6(struct sk_buff *skb, struct flowi *fl)
 {
-	u16 offset = sizeof(struct ipv6hdr);
+	u16 offset = skb->h.raw - skb->nh.raw;
 	struct ipv6hdr *hdr = skb->nh.ipv6h;
 	struct ipv6_opt_hdr *exthdr;
-	u8 nexthdr = skb->nh.ipv6h->nexthdr;
+	u8 nexthdr = skb->nh.raw[IP6CB(skb)->nhoff];
 
 	memset(fl, 0, sizeof(struct flowi));
 	ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr);