netfilter: nf_tables: validate NFPROTO_* family

Several expressions explicitly refer to NF_INET_* hook definitions
from expr->ops->validate, however, family is not validated.

Bail out with EOPNOTSUPP in case they are used from unsupported
families.

Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables")
Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression")
Fixes: 2fa841938c64 ("netfilter: nf_tables: introduce routing expression")
Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Fixes: ad49d86e07a4 ("netfilter: nf_tables: Add synproxy support")
Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support")
Fixes: 6c47260250fc ("netfilter: nf_tables: add xfrm expression")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nft_socket.c b/net/netfilter/nft_socket.c
index 9ed85be..f30163e 100644
--- a/net/netfilter/nft_socket.c
+++ b/net/netfilter/nft_socket.c
@@ -242,6 +242,11 @@ static int nft_socket_validate(const struct nft_ctx *ctx,
 			       const struct nft_expr *expr,
 			       const struct nft_data **data)
 {
+	if (ctx->family != NFPROTO_IPV4 &&
+	    ctx->family != NFPROTO_IPV6 &&
+	    ctx->family != NFPROTO_INET)
+		return -EOPNOTSUPP;
+
 	return nft_chain_validate_hooks(ctx->chain,
 					(1 << NF_INET_PRE_ROUTING) |
 					(1 << NF_INET_LOCAL_IN) |