netlabel: fix our progress tracking in netlbl_unlabel_staticlist()

The current NetLabel code doesn't correctly keep track of the netlink
dump state in some cases, in particular when multiple interfaces with
large configurations are loaded.  The problem manifests itself by not
reporting the full configuration to userspace, even though it is
loaded and active in the kernel.  This patch fixes this by ensuring
that the dump state is properly reset when necessary inside the
netlbl_unlabel_staticlist() function.

Fixes: 8cc4457 ("NetLabel: Introduce static network labels for unlabeled connections")
Signed-off-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/160484450633.3752.16512718263560813473.stgit@sifl
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/netlabel/netlabel_unlabeled.c

@@ -1166,12 +1166,13 @@ static int netlbl_unlabel_staticlist(struct sk_buff *skb,
 	struct netlbl_unlhsh_walk_arg cb_arg;
 	u32 skip_bkt = cb->args[0];
 	u32 skip_chain = cb->args[1];
-	u32 iter_bkt;
-	u32 iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0;
+	u32 skip_addr4 = cb->args[2];
+	u32 iter_bkt, iter_chain, iter_addr4 = 0, iter_addr6 = 0;
 	struct netlbl_unlhsh_iface *iface;
 	struct list_head *iter_list;
 	struct netlbl_af4list *addr4;
 #if IS_ENABLED(CONFIG_IPV6)
+	u32 skip_addr6 = cb->args[3];
 	struct netlbl_af6list *addr6;
 #endif
 
@@ -1182,15 +1183,15 @@ static int netlbl_unlabel_staticlist(struct sk_buff *skb,
 	rcu_read_lock();
 	for (iter_bkt = skip_bkt;
 	     iter_bkt < rcu_dereference(netlbl_unlhsh)->size;
-	     iter_bkt++, iter_chain = 0, iter_addr4 = 0, iter_addr6 = 0) {
+	     iter_bkt++) {
 		iter_list = &rcu_dereference(netlbl_unlhsh)->tbl[iter_bkt];
 		list_for_each_entry_rcu(iface, iter_list, list) {
 			if (!iface->valid ||
 			    iter_chain++ < skip_chain)
 				continue;
 			netlbl_af4list_foreach_rcu(addr4,
 						   &iface->addr4_list) {
-				if (iter_addr4++ < cb->args[2])
+				if (iter_addr4++ < skip_addr4)
 					continue;
 				if (netlbl_unlabel_staticlist_gen(
 					      NLBL_UNLABEL_C_STATICLIST,
@@ -1203,10 +1204,12 @@ static int netlbl_unlabel_staticlist(struct sk_buff *skb,
 					goto unlabel_staticlist_return;
 				}
 			}
+			iter_addr4 = 0;
+			skip_addr4 = 0;
 #if IS_ENABLED(CONFIG_IPV6)
 			netlbl_af6list_foreach_rcu(addr6,
 						   &iface->addr6_list) {
-				if (iter_addr6++ < cb->args[3])
+				if (iter_addr6++ < skip_addr6)
 					continue;
 				if (netlbl_unlabel_staticlist_gen(
 					      NLBL_UNLABEL_C_STATICLIST,
@@ -1219,8 +1222,12 @@ static int netlbl_unlabel_staticlist(struct sk_buff *skb,
 					goto unlabel_staticlist_return;
 				}
 			}
+			iter_addr6 = 0;
+			skip_addr6 = 0;
 #endif /* IPv6 */
 		}
+		iter_chain = 0;
+		skip_chain = 0;
 	}
 
 unlabel_staticlist_return: