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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, Pablo Neira Ayuso <pablo@netfilter.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 066/136] netfilter: nf_tables: disallow jump to implicit chain from set element
Date:   Mon, 29 Aug 2022 12:58:53 +0200
Message-Id: <20220829105807.331264599@linuxfoundation.org>
In-Reply-To: <20220829105804.609007228@linuxfoundation.org>
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From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit f323ef3a0d49e147365284bc1f02212e617b7f09 ]

Extend struct nft_data_desc to add a flag field that specifies
nft_data_init() is being called for set element data.

Use it to disallow jump to implicit chain from set element, only jump
to chain via immediate expression is allowed.

Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/net/netfilter/nf_tables.h | 5 +++++
 net/netfilter/nf_tables_api.c     | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 6a38bf8538f1e..53746494eb846 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -193,10 +193,15 @@ struct nft_ctx {
 	bool				report;
 };
 
+enum nft_data_desc_flags {
+	NFT_DATA_DESC_SETELEM	= (1 << 0),
+};
+
 struct nft_data_desc {
 	enum nft_data_types		type;
 	unsigned int			size;
 	unsigned int			len;
+	unsigned int			flags;
 };
 
 int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data,
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index b19f4255b9018..8bc4460b627ae 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5144,6 +5144,7 @@ static int nft_setelem_parse_data(struct nft_ctx *ctx, struct nft_set *set,
 	desc->type = dtype;
 	desc->size = NFT_DATA_VALUE_MAXLEN;
 	desc->len = set->dlen;
+	desc->flags = NFT_DATA_DESC_SETELEM;
 
 	return nft_data_init(ctx, data, desc, attr);
 }
@@ -9504,6 +9505,9 @@ static int nft_verdict_init(const struct nft_ctx *ctx, struct nft_data *data,
 			return PTR_ERR(chain);
 		if (nft_is_base_chain(chain))
 			return -EOPNOTSUPP;
+		if (desc->flags & NFT_DATA_DESC_SETELEM &&
+		    chain->flags & NFT_CHAIN_BINDING)
+			return -EINVAL;
 
 		chain->use++;
 		data->verdict.chain = chain;
-- 
2.35.1