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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Laura Garcia Liebana <nevola@gmail.com>,
        Pablo Neira Ayuso <pablo@netfilter.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 37/91] netfilter: nft_hash: fix symhash with modulus one
Date:   Wed, 14 Aug 2019 19:01:00 +0200
Message-Id: <20190814165751.247450065@linuxfoundation.org>
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[ Upstream commit 28b1d6ef53e3303b90ca8924bb78f31fa527cafb ]

The rule below doesn't work as the kernel raises -ERANGE.

nft add rule netdev nftlb lb01 ip daddr set \
	symhash mod 1 map { 0 : 192.168.0.10 } fwd to "eth0"

This patch allows to use the symhash modulus with one
element, in the same way that the other types of hashes and
algorithms that uses the modulus parameter.

Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nft_hash.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
index c2d237144f747..b8f23f75aea6c 100644
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -196,7 +196,7 @@ static int nft_symhash_init(const struct nft_ctx *ctx,
 	priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]);
 
 	priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS]));
-	if (priv->modulus <= 1)
+	if (priv->modulus < 1)
 		return -ERANGE;
 
 	if (priv->offset + priv->modulus - 1 < priv->offset)
-- 
2.20.1