From 7b1ba8de569460894efa892457af7a37c0d574f9 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 8 Aug 2006 16:48:51 -0700 Subject: [PATCH] [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 Signed-off-by: David S. Miller --- net/ipx/af_ipx.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c index c13e86b14f69..401964204866 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; -- 2.20.1