netfilter: nf_tables: imbalance in flowtable binding

BugLink: https://bugs.launchpad.net/bugs/2106770

[ Upstream commit 13210fc63f353fe78584048079343413a3cdf819 ]

All these cases cause imbalance between BIND and UNBIND calls:

- Delete an interface from a flowtable with multiple interfaces

- Add a (device to a) flowtable with --check flag

- Delete a netns containing a flowtable

- In an interactive nft session, create a table with owner flag and
  flowtable inside, then quit.

Fix it by calling FLOW_BLOCK_UNBIND when unregistering hooks, then
remove late FLOW_BLOCK_UNBIND call when destroying flowtable.

Fixes: ff4bf2f42a ("netfilter: nf_tables: add nft_unregister_flowtable_hook()")
Reported-by: Phil Sutter <phil@nwl.cc>
Tested-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Mehmet Basaran <mehmet.basaran@canonical.com>
This commit is contained in:
Pablo Neira Ayuso
2025-01-02 13:01:13 +01:00
committed by Mehmet Basaran
parent b2acfd499f
commit 044bdde4a6
+11 -4
View File
@@ -8491,6 +8491,7 @@ static void nft_unregister_flowtable_hook(struct net *net,
}
static void __nft_unregister_flowtable_net_hooks(struct net *net,
struct nft_flowtable *flowtable,
struct list_head *hook_list,
bool release_netdev)
{
@@ -8498,6 +8499,8 @@ static void __nft_unregister_flowtable_net_hooks(struct net *net,
list_for_each_entry_safe(hook, next, hook_list, list) {
nf_unregister_net_hook(net, &hook->ops);
flowtable->data.type->setup(&flowtable->data, hook->ops.dev,
FLOW_BLOCK_UNBIND);
if (release_netdev) {
list_del(&hook->list);
kfree_rcu(hook, rcu);
@@ -8506,9 +8509,10 @@ static void __nft_unregister_flowtable_net_hooks(struct net *net,
}
static void nft_unregister_flowtable_net_hooks(struct net *net,
struct nft_flowtable *flowtable,
struct list_head *hook_list)
{
__nft_unregister_flowtable_net_hooks(net, hook_list, false);
__nft_unregister_flowtable_net_hooks(net, flowtable, hook_list, false);
}
static int nft_register_flowtable_net_hooks(struct net *net,
@@ -9149,8 +9153,6 @@ static void nf_tables_flowtable_destroy(struct nft_flowtable *flowtable)
flowtable->data.type->free(&flowtable->data);
list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) {
flowtable->data.type->setup(&flowtable->data, hook->ops.dev,
FLOW_BLOCK_UNBIND);
list_del_rcu(&hook->list);
kfree_rcu(hook, rcu);
}
@@ -10515,6 +10517,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
&nft_trans_flowtable_hooks(trans),
trans->msg_type);
nft_unregister_flowtable_net_hooks(net,
nft_trans_flowtable(trans),
&nft_trans_flowtable_hooks(trans));
} else {
list_del_rcu(&nft_trans_flowtable(trans)->list);
@@ -10523,6 +10526,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
NULL,
trans->msg_type);
nft_unregister_flowtable_net_hooks(net,
nft_trans_flowtable(trans),
&nft_trans_flowtable(trans)->hook_list);
}
break;
@@ -10775,11 +10779,13 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
case NFT_MSG_NEWFLOWTABLE:
if (nft_trans_flowtable_update(trans)) {
nft_unregister_flowtable_net_hooks(net,
nft_trans_flowtable(trans),
&nft_trans_flowtable_hooks(trans));
} else {
nft_use_dec_restore(&trans->ctx.table->use);
list_del_rcu(&nft_trans_flowtable(trans)->list);
nft_unregister_flowtable_net_hooks(net,
nft_trans_flowtable(trans),
&nft_trans_flowtable(trans)->hook_list);
}
break;
@@ -11341,7 +11347,8 @@ static void __nft_release_hook(struct net *net, struct nft_table *table)
list_for_each_entry(chain, &table->chains, list)
__nf_tables_unregister_hook(net, table, chain, true);
list_for_each_entry(flowtable, &table->flowtables, list)
__nft_unregister_flowtable_net_hooks(net, &flowtable->hook_list,
__nft_unregister_flowtable_net_hooks(net, flowtable,
&flowtable->hook_list,
true);
}