Commit 938177e9 authored May 30, 2013 by Simon Horman Committed by David S. Miller May 31, 2013

netfilter: Correct calculation using skb->tail and skb-network_header



This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->network_header
will be an offset from head. This is corrected by using wrappers that
ensure that calculations are always made using pointers.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent db8caf3d

net/netfilter/nf_nat_helper.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -104,7 +104,7 @@ static void mangle_contents(struct sk_buff *skb,
		/* move post-replacement */
		memmove(data + match_offset + rep_len,
		data + match_offset + match_len,
		skb->tail - (skb->network_header + dataoff +
		skb_tail_pointer(skb) - (skb_network_header(skb) + dataoff +
		match_offset + match_len));

		/* insert data from buffer */