diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c489a1e6aec9a8b05a46bcf36424c30d73ebc8f0..0e765466d7f79ecc13316204c4ffc29c7ea3a71b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4821,7 +4821,7 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
                              ifm->ifa_prefixlen, extack);
 }
 
-static int modify_prefix_route(struct inet6_ifaddr *ifp,
+static int modify_prefix_route(struct net *net, struct inet6_ifaddr *ifp,
                               unsigned long expires, u32 flags,
                               bool modify_peer)
 {
@@ -4845,7 +4845,9 @@ static int modify_prefix_route(struct inet6_ifaddr *ifp,
                                      ifp->prefix_len,
                                      ifp->rt_priority, ifp->idev->dev,
                                      expires, flags, GFP_KERNEL);
-       } else {
+               return 0;
+       }
+       if (f6i != net->ipv6.fib6_null_entry) {
                table = f6i->fib6_table;
                spin_lock_bh(&table->tb6_lock);
 
@@ -4858,9 +4860,8 @@ static int modify_prefix_route(struct inet6_ifaddr *ifp,
                }
 
                spin_unlock_bh(&table->tb6_lock);
-
-               fib6_info_release(f6i);
        }
+       fib6_info_release(f6i);
 
        return 0;
 }
@@ -4939,7 +4940,7 @@ static int inet6_addr_modify(struct net *net, struct inet6_ifaddr *ifp,
                int rc = -ENOENT;
 
                if (had_prefixroute)
-                       rc = modify_prefix_route(ifp, expires, flags, false);
+                       rc = modify_prefix_route(net, ifp, expires, flags, false);
 
                /* prefix route could have been deleted; if so restore it */
                if (rc == -ENOENT) {
@@ -4949,7 +4950,7 @@ static int inet6_addr_modify(struct net *net, struct inet6_ifaddr *ifp,
                }
 
                if (had_prefixroute && !ipv6_addr_any(&ifp->peer_addr))
-                       rc = modify_prefix_route(ifp, expires, flags, true);
+                       rc = modify_prefix_route(net, ifp, expires, flags, true);
 
                if (rc == -ENOENT && !ipv6_addr_any(&ifp->peer_addr)) {
                        addrconf_prefix_route(&ifp->peer_addr, ifp->prefix_len,