bool ipv6_chk_custom_prefix(const struct in6_addr *addr,
        const unsigned int prefix_len, struct net_device *dev)
 {
-       struct inet6_dev *idev;
-       struct inet6_ifaddr *ifa;
+       const struct inet6_ifaddr *ifa;
+       const struct inet6_dev *idev;
        bool ret = false;
 
        rcu_read_lock();
        idev = __in6_dev_get(dev);
        if (idev) {
-               read_lock_bh(&idev->lock);
-               list_for_each_entry(ifa, &idev->addr_list, if_list) {
+               list_for_each_entry_rcu(ifa, &idev->addr_list, if_list) {
                        ret = ipv6_prefix_equal(addr, &ifa->addr, prefix_len);
                        if (ret)
                                break;
                }
-               read_unlock_bh(&idev->lock);
        }
        rcu_read_unlock();