[PATCH 5.19 0140/1157] netfilter: nf_tables: do not allow SET_ID to refer to another table

Greg Kroah-Hartman
2022-08-15T22:28:48Z

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
@@ -3842,6 +3842,7 @@ 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 nftables_pernet *nft_net = nft_pernet(net);
@@ -3853,6 +3854,7 @@ 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;
}
@@ -3873,7 +3875,7 @@ 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;
}