[PATCH nf] netfilter: nf_tables: release objects on netns destruction

[PATCH nf] netfilter: nf_tables: release objects on netns destruction

[Pablo Neira Ayuso]

We have to release the existing objects on netns removal otherwise we
leak them.

Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 93cc473..428b90a 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4584,7 +4584,7 @@ int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data,
 }
 EXPORT_SYMBOL_GPL(nft_data_dump);
 
-static int nf_tables_init_net(struct net *net)
+static int __net_init nf_tables_init_net(struct net *net)
 {
 	INIT_LIST_HEAD(&net->nft.af_info);
 	INIT_LIST_HEAD(&net->nft.commit_list);
@@ -4592,8 +4592,47 @@ static int nf_tables_init_net(struct net *net)
 	return 0;
 }
 
+static void __net_exit nf_tables_exit_net(struct net *net)
+{
+	struct nft_table *table, *nt;
+	struct nft_chain *chain, *nc;
+	struct nft_rule *rule, *nr;
+	struct nft_set *set, *ns;
+	struct nft_af_info *afi;
+	struct nft_ctx ctx;
+
+	nfnl_lock(NFNL_SUBSYS_NFTABLES);
+	list_for_each_entry(afi, &net->nft.af_info, list) {
+		ctx.afi = afi;
+		list_for_each_entry_safe(table, nt, &afi->tables, list) {
+			ctx.table = table;
+			list_for_each_entry(chain, &table->chains, list) {
+				ctx.chain = chain;
+				list_for_each_entry_safe(rule, nr, &chain->rules, list) {
+					list_del(&rule->list);
+					nf_tables_rule_destroy(&ctx, rule);
+				}
+			}
+			list_for_each_entry_safe(chain, nc, &table->chains, list) {
+				list_del(&chain->list);
+				nf_tables_unregister_hooks(table, chain,
+							   afi->nops);
+				nf_tables_chain_destroy(chain);
+			}
+			list_for_each_entry_safe(set, ns, &table->sets, list) {
+				list_del(&set->list);
+				nft_set_destroy(set);
+			}
+			list_del(&table->list);
+			nf_tables_table_destroy(&ctx);
+		}
+	}
+	nfnl_unlock(NFNL_SUBSYS_NFTABLES);
+}
+
 static struct pernet_operations nf_tables_net_ops = {
 	.init	= nf_tables_init_net,
+	.exit	= nf_tables_exit_net,
 };
 
 static int __init nf_tables_module_init(void)
-- 
2.1.4