[PATCH 5.4 125/155] netfilter: nft_fwd_netdev: validate family and chain type

Greg Kroah-Hartman
2020-03-31T09:17:19Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

commit 76a109fac206e158eb3c967af98c178cff738e6a upstream.

Make sure the forward action is only used from ingress.

Fixes: 39e6dea28adc ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/netfilter/nft_fwd_netdev.c | 9 +++++++++
1 file changed, 9 insertions(+)

--- a/net/netfilter/nft_fwd_netdev.c
+++ b/net/netfilter/nft_fwd_netdev.c
@@ -190,6 +190,13 @@ nla_put_failure:
return -1;
}

+static int nft_fwd_validate(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nft_data **data)
+{
+ return nft_chain_validate_hooks(ctx->chain, (1 << NF_NETDEV_INGRESS));
+}
+
static struct nft_expr_type nft_fwd_netdev_type;
static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = {
.type = &nft_fwd_netdev_type,
@@ -197,6 +204,7 @@ static const struct nft_expr_ops nft_fwd
.eval = nft_fwd_neigh_eval,
.init = nft_fwd_neigh_init,
.dump = nft_fwd_neigh_dump,
+ .validate = nft_fwd_validate,
};

static const struct nft_expr_ops nft_fwd_netdev_ops = {
@@ -205,6 +213,7 @@ static const struct nft_expr_ops nft_fwd
.eval = nft_fwd_netdev_eval,
.init = nft_fwd_netdev_init,
.dump = nft_fwd_netdev_dump,
+ .validate = nft_fwd_validate,
.offload = nft_fwd_netdev_offload,
};