From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Date: Tue, 9 Aug 2022 14:01:46 -0300
Subject: netfilter: nf_tables: do not allow SET_ID to refer to another table
Patch-mainline: v6.0-rc1
Git-commit: 470ee20e069a6d05ae549f7d0ef2bdbcee6a81b2
References: CVE-2022-2586 bsc#1202095
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>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
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
@@ -3730,6 +3730,7 @@ 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);
@@ -3741,6 +3742,7 @@ 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;
}
@@ -3761,7 +3763,7 @@ 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;
}