netfilter: nf_tables: Introduce functions freeing nft_hook objects

JIRA: https://issues.redhat.com/browse/RHEL-115582
Upstream Status: commit 75e20bc

commit 75e20bc
Author: Phil Sutter <phil@nwl.cc>
Date:   Wed May 21 22:44:22 2025 +0200

    netfilter: nf_tables: Introduce functions freeing nft_hook objects

    Pointless wrappers around kfree() for now, prep work for an embedded
    list of nf_hook_ops.

    Signed-off-by: Phil Sutter <phil@nwl.cc>
    Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: Florian Westphal <fwestpha@redhat.com>

Author: fw-strlen

net/netfilter/nf_tables_api.c

@@ -323,6 +323,16 @@ static int nft_netdev_register_hooks(struct net *net,
 	return err;
 }
 
+static void nft_netdev_hook_free(struct nft_hook *hook)
+{
+	kfree(hook);
+}
+
+static void nft_netdev_hook_free_rcu(struct nft_hook *hook)
+{
+	kfree_rcu(hook, rcu);
+}
+
 static void nft_netdev_unregister_hooks(struct net *net,
 					struct list_head *hook_list,
 					bool release_netdev)
@@ -333,7 +343,7 @@ static void nft_netdev_unregister_hooks(struct net *net,
 		nf_unregister_net_hook(net, &hook->ops);
 		if (release_netdev) {
 			list_del(&hook->list);
-			kfree_rcu(hook, rcu);
+			nft_netdev_hook_free_rcu(hook);
 		}
 	}
 }
@@ -2252,7 +2262,7 @@ void nf_tables_chain_destroy(struct nft_chain *chain)
 			list_for_each_entry_safe(hook, next,
 						 &basechain->hook_list, list) {
 				list_del_rcu(&hook->list);
-				kfree_rcu(hook, rcu);
+				nft_netdev_hook_free_rcu(hook);
 			}
 		}
 		module_put(basechain->type->owner);
@@ -2340,7 +2350,7 @@ static int nf_tables_parse_netdev_hooks(struct net *net,
 		}
 		if (nft_hook_list_find(hook_list, hook)) {
 			NL_SET_BAD_ATTR(extack, tmp);
-			kfree(hook);
+			nft_netdev_hook_free(hook);
 			err = -EEXIST;
 			goto err_hook;
 		}
@@ -2358,7 +2368,7 @@ static int nf_tables_parse_netdev_hooks(struct net *net,
 err_hook:
 	list_for_each_entry_safe(hook, next, hook_list, list) {
 		list_del(&hook->list);
-		kfree(hook);
+		nft_netdev_hook_free(hook);
 	}
 	return err;
 }
@@ -2501,7 +2511,7 @@ static void nft_chain_release_hook(struct nft_chain_hook *hook)
 
 	list_for_each_entry_safe(h, next, &hook->list, list) {
 		list_del(&h->list);
-		kfree(h);
+		nft_netdev_hook_free(h);
 	}
 	module_put(hook->type->owner);
 }
@@ -2790,7 +2800,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
 
 				if (nft_hook_list_find(&basechain->hook_list, h)) {
 					list_del(&h->list);
-					kfree(h);
+					nft_netdev_hook_free(h);
 				}
 			}
 		} else {
@@ -2911,7 +2921,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
 			if (unregister)
 				nf_unregister_net_hook(ctx->net, &h->ops);
 			list_del(&h->list);
-			kfree_rcu(h, rcu);
+			nft_netdev_hook_free_rcu(h);
 		}
 		module_put(hook.type->owner);
 	}
@@ -8902,7 +8912,7 @@ static void __nft_unregister_flowtable_net_hooks(struct net *net,
 					    FLOW_BLOCK_UNBIND);
 		if (release_netdev) {
 			list_del(&hook->list);
-			kfree_rcu(hook, rcu);
+			nft_netdev_hook_free_rcu(hook);
 		}
 	}
 }
@@ -8963,7 +8973,7 @@ static int nft_register_flowtable_net_hooks(struct net *net,
 
 		nft_unregister_flowtable_hook(net, flowtable, hook);
 		list_del_rcu(&hook->list);
-		kfree_rcu(hook, rcu);
+		nft_netdev_hook_free_rcu(hook);
 	}
 
 	return err;
@@ -8975,7 +8985,7 @@ static void nft_hooks_destroy(struct list_head *hook_list)
 
 	list_for_each_entry_safe(hook, next, hook_list, list) {
 		list_del_rcu(&hook->list);
-		kfree_rcu(hook, rcu);
+		nft_netdev_hook_free_rcu(hook);
 	}
 }
 
@@ -8999,7 +9009,7 @@ static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh,
 	list_for_each_entry_safe(hook, next, &flowtable_hook.list, list) {
 		if (nft_hook_list_find(&flowtable->hook_list, hook)) {
 			list_del(&hook->list);
-			kfree(hook);
+			nft_netdev_hook_free(hook);
 		}
 	}
 
@@ -9046,7 +9056,7 @@ static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh,
 		if (unregister)
 			nft_unregister_flowtable_hook(ctx->net, flowtable, hook);
 		list_del_rcu(&hook->list);
-		kfree_rcu(hook, rcu);
+		nft_netdev_hook_free_rcu(hook);
 	}
 
 	return err;
@@ -9192,7 +9202,7 @@ static void nft_flowtable_hook_release(struct nft_flowtable_hook *flowtable_hook
 
 	list_for_each_entry_safe(this, next, &flowtable_hook->list, list) {
 		list_del(&this->list);
-		kfree(this);
+		nft_netdev_hook_free(this);
 	}
 }
 
@@ -9554,7 +9564,7 @@ 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) {
 		list_del_rcu(&hook->list);
-		kfree_rcu(hook, rcu);
+		nft_netdev_hook_free_rcu(hook);
 	}
 	kfree(flowtable->name);
 	module_put(flowtable->data.type->owner);