Commit 8dc3c2b8 authored Sep 15, 2016 by Liping Zhang Committed by Pablo Neira Ayuso Sep 23, 2016

netfilter: nf_tables: improve nft payload fast eval



There's an off-by-one issue in nft_payload_fast_eval, skb_tail_pointer
and ptr + priv->len all point to the last valid address plus 1. So if
they are equal, we can still fetch the valid data. It's unnecessary to
fall back to nft_payload_eval.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent 2462f3f4

net/netfilter/nf_tables_core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -98,7 +98,7 @@ static bool nft_payload_fast_eval(const struct nft_expr *expr,

		ptr += priv->offset;

		if (unlikely(ptr + priv->len >= skb_tail_pointer(skb)))
		if (unlikely(ptr + priv->len > skb_tail_pointer(skb)))
		return false;

		*dest = 0;