[PATCH 4.19 17/30] netfilter: nft_nat: allow to specify layer 4 protocol NAT only

[Greg Kroah-Hartman]

From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

[ Upstream commit a33f387ecd5aafae514095c2c4a8c24f7aea7e8b ]

nft_nat reports a bogus EAFNOSUPPORT if no layer 3 information is specified.

Fixes: d07db9884a5f ("netfilter: nf_tables: introduce nft_validate_register_load()")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/netfilter/nft_nat.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c
index 3e82a7d0df2a..2c3d7ff6f58a 100644
--- a/net/netfilter/nft_nat.c
+++ b/net/netfilter/nft_nat.c
@@ -153,7 +153,9 @@ static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
 		alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip6);
 		break;
 	default:
-		return -EAFNOSUPPORT;
+		if (tb[NFTA_NAT_REG_ADDR_MIN])
+			return -EAFNOSUPPORT;
+		break;
 	}
 	priv->family = family;
 
-- 
2.30.2