From 4759c55ff1d52074bde823cb9931377ee1f6051a Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 10 Jun 2021 20:20:30 +0200 Subject: [PATCH] netfilter: nft_exthdr: check for IPv6 packet before further processing [ Upstream commit cdd73cc545c0fb9b1a1f7b209f4f536e7990cff4 ] ipv6_find_hdr() does not validate that this is an IPv6 packet. Add a sanity check for calling ipv6_find_hdr() to make sure an IPv6 packet is passed for parsing. Fixes: 96518518cc41 ("netfilter: add nftables") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nft_exthdr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index 427d77b111b1..00f4323cfeb8 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -42,6 +42,9 @@ static void nft_exthdr_ipv6_eval(const struct nft_expr *expr, unsigned int offset = 0; int err; + if (pkt->skb->protocol != htons(ETH_P_IPV6)) + goto err; + err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL); if (priv->flags & NFT_EXTHDR_F_PRESENT) { nft_reg_store8(dest, err >= 0);