[ 470ee20e069a6d05ae549f7d0ef2bdbcee6a81b2 ]
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 --- include/net/netfilter/nf_tables.h | 2 ++ net/netfilter/nf_tables_api.c | 7 +++++-- 2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 4eb90800fc2e..0d625ff7841a 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -381,6 +381,7 @@ void nft_unregister_set(struct nft_set_type *type); * * @list: table set list node * @bindings: list of set bindings + * @table: table this set belongs to * @name: name of the set * @ktype: key type (numeric type defined by userspace, not used in the kernel) * @dtype: data type (verdict or numeric type defined by userspace) @@ -404,6 +405,7 @@ void nft_unregister_set(struct nft_set_type *type); struct nft_set { struct list_head list; struct list_head bindings; + struct nft_table *table; char *name; u32 ktype; u32 dtype; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 86913d53eead..345fa29f34b9 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2746,6 +2746,7 @@ static struct nft_set *nf_tables_set_lookup(const struct nft_table *table, }
static struct nft_set *nf_tables_set_lookup_byid(const struct net *net, + const struct nft_table *table, const struct nlattr *nla, u8 genmask) { @@ -2757,6 +2758,7 @@ static struct nft_set *nf_tables_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; } @@ -2777,7 +2779,7 @@ struct nft_set *nft_set_lookup(const struct net *net, if (!nla_set_id) return set;
- set = nf_tables_set_lookup_byid(net, nla_set_id, genmask); + set = nf_tables_set_lookup_byid(net, table, nla_set_id, genmask); } return set; } @@ -3272,6 +3274,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk, }
INIT_LIST_HEAD(&set->bindings); + set->table = table; set->ops = ops; set->ktype = ktype; set->klen = desc.klen; @@ -4209,7 +4212,7 @@ static int nf_tables_newsetelem(struct net *net, struct sock *nlsk, genmask); if (IS_ERR(set)) { if (nla[NFTA_SET_ELEM_LIST_SET_ID]) { - set = nf_tables_set_lookup_byid(net, + set = nf_tables_set_lookup_byid(net, ctx.table, nla[NFTA_SET_ELEM_LIST_SET_ID], genmask); }