From 540436c80e5918dd5ed838449e108b1726fc4d68 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 20 Dec 2013 11:23:15 +0100 Subject: [PATCH] netfilter: nft_exthdr: call ipv6_find_hdr() with explicitly initialized offset In nft's nft_exthdr_eval() routine we process IPv6 extension header through invoking ipv6_find_hdr(), but we call it with an uninitialized offset variable that contains some stack value. In ipv6_find_hdr() we then test if the value of offset != 0 and call skb_header_pointer() on that offset in order to map struct ipv6hdr into it. Fix it up by initializing offset to 0 as it was probably intended to be. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Daniel Borkmann Cc: Hannes Frederic Sowa Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_exthdr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index 8e0bb75e7c51..55c939f5371f 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -31,7 +31,7 @@ static void nft_exthdr_eval(const struct nft_expr *expr, { struct nft_exthdr *priv = nft_expr_priv(expr); struct nft_data *dest = &data[priv->dreg]; - unsigned int offset; + unsigned int offset = 0; int err; err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);