fib: Fix fib zone and its hash leak on namespace stop

When we stop a namespace we flush the table and free one, but the
added fn_zone-s (and their hashes if grown) are leaked. Need to free.
Tries releases all its stuff in the flushing code.

Shame on us - this bug exists since the very first make-fib-per-net
patches in 2.6.27 :(
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/ip_fib.h

@@ -158,6 +158,8 @@ extern int fib_table_flush(struct fib_table *table);
 extern void fib_table_select_default(struct fib_table *table,
 				     const struct flowi *flp,
 				     struct fib_result *res);
+extern void fib_free_table(struct fib_table *tb);
+
 
 
 #ifndef CONFIG_IP_MULTIPLE_TABLES

net/ipv4/fib_frontend.c

@@ -1052,7 +1052,7 @@ static void ip_fib_net_exit(struct net *net)
 		hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
 			hlist_del(node);
 			fib_table_flush(tb);
-			kfree(tb);
+			fib_free_table(tb);
 		}
 	}
 	kfree(net->ipv4.fib_table_hash);

net/ipv4/fib_hash.c

@@ -716,6 +716,24 @@ int fib_table_flush(struct fib_table *tb)
 	return found;
 }
 
+void fib_free_table(struct fib_table *tb)
+{
+	struct fn_hash *table = (struct fn_hash *) tb->tb_data;
+	struct fn_zone *fz, *next;
+
+	next = table->fn_zone_list;
+	while (next != NULL) {
+		fz = next;
+		next = fz->fz_next;
+
+		if (fz->fz_hash != fz->fz_embedded_hash)
+			fz_hash_free(fz->fz_hash, fz->fz_divisor);
+
+		kfree(fz);
+	}
+
+	kfree(tb);
+}
 
 static inline int
 fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,

net/ipv4/fib_trie.c

@@ -1797,6 +1797,11 @@ int fib_table_flush(struct fib_table *tb)
 	return found;
 }
 
+void fib_free_table(struct fib_table *tb)
+{
+	kfree(tb);
+}
+
 void fib_table_select_default(struct fib_table *tb,
 			      const struct flowi *flp,
 			      struct fib_result *res)