Revert "netfilter: ipset: remove set destroy at ip_set module removal"

In case of namespace exit the modules are not unloaded but the sets belonging
to the namespace must be destroyed.

This reverts commit 099916e8f2c0a9c84f79469a8db49f775d4af16e.

Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>

1 files changed, 24 insertions, 3 deletions

diff --git a/kernel/net/netfilter/ipset/ip_set_core.c b/kernel/net/netfilter/ipset/ip_set_core.c
index c31dbc3..a99c1bd 100644
--- a/kernel/net/netfilter/ipset/ip_set_core.c
+++ b/kernel/net/netfilter/ipset/ip_set_core.c
@@ -30,6 +30,7 @@ static DEFINE_RWLOCK(ip_set_ref_lock);		/* protects the set refs */
 struct ip_set_net {
 	struct ip_set * __rcu *ip_set_list;	/* all individual sets */
 	ip_set_id_t	ip_set_max;	/* max number of sets */
+	bool		is_deleted;	/* deleted by ip_set_net_exit */
 	bool		is_destroyed;	/* all sets are destroyed */
 };
 
@@ -925,9 +926,11 @@ ip_set_nfnl_put(struct net *net, ip_set_id_t index)
 	struct ip_set_net *inst = ip_set_pernet(net);
 
 	nfnl_lock(NFNL_SUBSYS_IPSET);
-	set = ip_set(inst, index);
-	if (set)
-		__ip_set_put(set);
+	if (!inst->is_deleted) { /* already deleted from ip_set_net_exit() */
+		set = ip_set(inst, index);
+		if (set)
+			__ip_set_put(set);
+	}
 	nfnl_unlock(NFNL_SUBSYS_IPSET);
 }
 EXPORT_SYMBOL_GPL(ip_set_nfnl_put);
@@ -2481,6 +2484,7 @@ ip_set_net_init(struct net *net)
 #else
 		goto err_alloc;
 #endif
+	inst->is_deleted = false;
 	inst->is_destroyed = false;
 	rcu_assign_pointer(inst->ip_set_list, list);
 	return 0;
@@ -2497,6 +2501,20 @@ ip_set_net_exit(struct net *net)
 {
 	struct ip_set_net *inst = ip_set_pernet(net);
 
+	struct ip_set *set = NULL;
+	ip_set_id_t i;
+
+	inst->is_deleted = true; /* flag for ip_set_nfnl_put */
+
+	nfnl_lock(NFNL_SUBSYS_IPSET);
+	for (i = 0; i < inst->ip_set_max; i++) {
+		set = ip_set(inst, i);
+		if (set) {
+			ip_set(inst, i) = NULL;
+			ip_set_destroy_set(set);
+		}
+	}
+	nfnl_unlock(NFNL_SUBSYS_IPSET);
 	kvfree(rcu_dereference_protected(inst->ip_set_list, 1));
 #ifndef HAVE_NET_OPS_ID
 	kvfree(inst);
@@ -2563,6 +2581,9 @@ ip_set_fini(void)
 	nfnetlink_subsys_unregister(&ip_set_netlink_subsys);
 	UNREGISTER_PERNET_SUBSYS(&ip_set_net_ops);
 
+	/* Wait for call_rcu() in destroy */
+	rcu_barrier();
+
 	pr_debug("these are the famous last words\n");
 }