From: Stephen Hemminger <shemminger@osdl.org>
Date: Tue, 8 Aug 2006 23:48:51 +0000 (-0700)
Subject: [IPX]: Another nonlinear receive fix
X-Git-Tag: v2.6.18-rc5~121^2~1
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=7b1ba8de569460894efa892457af7a37c0d574f9;p=~emulex%2Finfiniband.git

[IPX]: Another nonlinear receive fix

Need to check some more cases in IPX receive.  If the skb is purely
fragments, the IPX header needs to be extracted. The function
pskb_may_pull() may in theory invalidate all the pointers in the skb,
so references to ipx header must be refreshed.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c
index c13e86b14f6..40196420486 100644
--- a/net/ipx/af_ipx.c
+++ b/net/ipx/af_ipx.c
@@ -1642,14 +1642,17 @@ static int ipx_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_ty
 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
 		goto out;
 
-	ipx		= ipx_hdr(skb);
-	ipx_pktsize	= ntohs(ipx->ipx_pktsize);
+	if (!pskb_may_pull(skb, sizeof(struct ipxhdr)))
+		goto drop;
+
+	ipx_pktsize = ntohs(ipxhdr(skb)->ipx_pktsize);
 	
 	/* Too small or invalid header? */
 	if (ipx_pktsize < sizeof(struct ipxhdr) ||
 	    !pskb_may_pull(skb, ipx_pktsize))
 		goto drop;
                         
+	ipx = ipx_hdr(skb);
 	if (ipx->ipx_checksum != IPX_NO_CHECKSUM &&
 	   ipx->ipx_checksum != ipx_cksum(ipx, ipx_pktsize))
 		goto drop;