[PATCH 4.9 069/102] netfilter: nft_fwd_netdev: validate family and chain type

From: Greg Kroah-Hartman
Date: Wed Apr 01 2020 - 12:39:08 EST


From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/netfilter/nft_fwd_netdev.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/net/netfilter/nft_fwd_netdev.c
+++ b/net/netfilter/nft_fwd_netdev.c
@@ -62,6 +62,13 @@ 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_netdev_ops = {
.type = &nft_fwd_netdev_type,
@@ -69,6 +76,7 @@ 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,
};

static struct nft_expr_type nft_fwd_netdev_type __read_mostly = {