netfilter: nf_tables: do not allow SET_ID to refer to another table

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: 8406eef378c0 ("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>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 3b09e13b9b5c87d3704242674098f058b0f3c4db..41c529b0001cb4e0a39db371ad157974f93181bb 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3842,6 +3842,7 @@ static struct nft_set *nft_set_lookup_byhandle(const struct nft_table *table,
 }
 
 static struct nft_set *nft_set_lookup_byid(const struct net *net,
+                                          const struct nft_table *table,
                                           const struct nlattr *nla, u8 genmask)
 {
        struct nftables_pernet *nft_net = nft_pernet(net);
@@ -3853,6 +3854,7 @@ static struct nft_set *nft_set_lookup_byid(const struct net *net,
                        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;
                }
@@ -3873,7 +3875,7 @@ struct nft_set *nft_set_lookup_global(const struct net *net,
                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;
 }