Patch "netfilter: nf_tables: imbalance in flowtable binding" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    netfilter: nf_tables: imbalance in flowtable binding

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-nf_tables-imbalance-in-flowtable-binding.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit d43ccc9c3761dfd41fdd81449f2a82d4ee1edfba
Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date:   Thu Jan 2 13:01:13 2025 +0100

    netfilter: nf_tables: imbalance in flowtable binding
    
    [ 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: ff4bf2f42a40 ("netfilter: nf_tables: add nft_unregister_flowtable_hook()")
    Reported-by: Phil Sutter <phil@xxxxxx>
    Tested-by: Phil Sutter <phil@xxxxxx>
    Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 07bcf9b7d779..8176533c50ab 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7979,6 +7979,7 @@ 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)
 {
@@ -7986,6 +7987,8 @@ 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);
@@ -7994,9 +7997,10 @@ 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,
@@ -8618,8 +8622,6 @@ 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);
 	}
@@ -9902,6 +9904,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 							   &nft_trans_flowtable_hooks(trans),
 							   NFT_MSG_DELFLOWTABLE);
 				nft_unregister_flowtable_net_hooks(net,
+								   nft_trans_flowtable(trans),
 								   &nft_trans_flowtable_hooks(trans));
 			} else {
 				list_del_rcu(&nft_trans_flowtable(trans)->list);
@@ -9910,6 +9913,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 							   &nft_trans_flowtable(trans)->hook_list,
 							   NFT_MSG_DELFLOWTABLE);
 				nft_unregister_flowtable_net_hooks(net,
+						nft_trans_flowtable(trans),
 						&nft_trans_flowtable(trans)->hook_list);
 			}
 			break;
@@ -10140,11 +10144,13 @@ 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;
@@ -10685,7 +10691,8 @@ 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);
 }