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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,
        Thadeu Lima de Souza Cascardo <cascardo@canonical.com>,
        Pablo Neira Ayuso <pablo@netfilter.org>
Subject: [PATCH 4.19 037/287] netfilter: nf_tables: do not allow SET_ID to refer to another table
Date:   Tue, 23 Aug 2022 10:23:26 +0200
Message-Id: <20220823080101.519704894@linuxfoundation.org>
In-Reply-To: <20220823080100.268827165@linuxfoundation.org>
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From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

commit 470ee20e069a6d05ae549f7d0ef2bdbcee6a81b2 upstream.

When doing lookups for sets on the same batch by using its ID, a set from a
different table can be used.

Then, when the table is removed, a reference to the set may be kept after
the set is freed, leading to a potential use-after-free.

When looking for sets by ID, use the table that was used for the lookup by
name, and only return sets belonging to that same table.

This fixes CVE-2022-2586, also reported as ZDI-CAN-17470.

Reported-by: Team Orca of Sea Security (@seasecresponse)
Fixes: 958bee14d071 ("netfilter: nf_tables: use new transaction infrastructure to handle sets")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/netfilter/nf_tables_api.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3039,6 +3039,7 @@ static struct nft_set *nft_set_lookup_by
 }
 
 static struct nft_set *nft_set_lookup_byid(const struct net *net,
+					   const struct nft_table *table,
 					   const struct nlattr *nla, u8 genmask)
 {
 	struct nft_trans *trans;
@@ -3049,6 +3050,7 @@ static struct nft_set *nft_set_lookup_by
 			struct nft_set *set = nft_trans_set(trans);
 
 			if (id == nft_trans_set_id(trans) &&
+			    set->table == table &&
 			    nft_active_genmask(set, genmask))
 				return set;
 		}
@@ -3069,7 +3071,7 @@ struct nft_set *nft_set_lookup_global(co
 		if (!nla_set_id)
 			return set;
 
-		set = nft_set_lookup_byid(net, nla_set_id, genmask);
+		set = nft_set_lookup_byid(net, table, nla_set_id, genmask);
 	}
 	return set;
 }