diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 5d96cbf76134..82b6f603faa0 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -6482,20 +6482,19 @@ static int addrconf_sysctl_disable(const struct ctl_table *ctl, int write,
 static int addrconf_sysctl_proxy_ndp(const struct ctl_table *ctl, int write,
 		void *buffer, size_t *lenp, loff_t *ppos)
 {
+	struct net *net = ctl->extra2;
 	int *valp = ctl->data;
-	int ret;
 	int old, new;
+	int ret;
+
+	if (write && !rtnl_net_trylock(net))
+		return restart_syscall();
 
 	old = *valp;
 	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
 	new = *valp;
 
 	if (write && old != new) {
-		struct net *net = ctl->extra2;
-
-		if (!rtnl_net_trylock(net))
-			return restart_syscall();
-
 		if (valp == &net->ipv6.devconf_dflt->proxy_ndp) {
 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
 						     NETCONFA_PROXY_NEIGH,
@@ -6514,8 +6513,9 @@ static int addrconf_sysctl_proxy_ndp(const struct ctl_table *ctl, int write,
 						     idev->dev->ifindex,
 						     &idev->cnf);
 		}
-		rtnl_net_unlock(net);
 	}
+	if (write)
+		rtnl_net_unlock(net);
 
 	return ret;
 }