From f627ed91d85ed7a189ec8b3b045a0d831e1655e2 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Sun, 16 Feb 2014 14:01:58 +0100 Subject: [PATCH] netfilter: nf_tables: check if payload length is a power of 2 Add a check if payload's length is a power of 2 when selecting ops. The fast ops were meant for well aligned loads, also this fixes a small bug when using a length of 3 with some offsets which causes only 1 byte to be loaded because the fast ops are chosen. Signed-off-by: Nikolay Aleksandrov Acked-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_payload.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index a2aeb318678f..85daa84bfdfe 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -135,7 +135,8 @@ nft_payload_select_ops(const struct nft_ctx *ctx, if (len == 0 || len > FIELD_SIZEOF(struct nft_data, data)) return ERR_PTR(-EINVAL); - if (len <= 4 && IS_ALIGNED(offset, len) && base != NFT_PAYLOAD_LL_HEADER) + if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) && + base != NFT_PAYLOAD_LL_HEADER) return &nft_payload_fast_ops; else return &nft_payload_ops; -- 2.11.0