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 <pablo@xxxxxxxxxxxxx>
---
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 7f705b5c09de..d8f03175879f 100644
--- a/net/netfilter/nft_exthdr.c
+++ b/net/netfilter/nft_exthdr.c
@@ -44,6 +44,9 @@ static void nft_exthdr_ipv6_eval(const struct nft_expr *expr,
unsigned int offset = 0;
int err;
+ if (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);
--
2.20.1
