diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 9bae409..2bd23ea 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -383,7 +383,10 @@
 static inline struct ip_map *
 ip_map_cached_get(struct svc_rqst *rqstp)
 {
-	struct ip_map *ipm = rqstp->rq_sock->sk_info_authunix;
+	struct ip_map *ipm;
+	struct svc_sock *svsk = rqstp->rq_sock;
+	spin_lock_bh(&svsk->sk_defer_lock);
+	ipm = svsk->sk_info_authunix;
 	if (ipm != NULL) {
 		if (!cache_valid(&ipm->h)) {
 			/*
@@ -391,12 +394,14 @@
 			 * remembered, e.g. by a second mount from the
 			 * same IP address.
 			 */
-			rqstp->rq_sock->sk_info_authunix = NULL;
+			svsk->sk_info_authunix = NULL;
+			spin_unlock_bh(&svsk->sk_defer_lock);
 			cache_put(&ipm->h, &ip_map_cache);
 			return NULL;
 		}
 		cache_get(&ipm->h);
 	}
+	spin_unlock_bh(&svsk->sk_defer_lock);
 	return ipm;
 }
 
@@ -405,9 +410,15 @@
 {
 	struct svc_sock *svsk = rqstp->rq_sock;
 
-	if (svsk->sk_sock->type == SOCK_STREAM && svsk->sk_info_authunix == NULL)
-		svsk->sk_info_authunix = ipm;	/* newly cached, keep the reference */
-	else
+	spin_lock_bh(&svsk->sk_defer_lock);
+	if (svsk->sk_sock->type == SOCK_STREAM &&
+	    svsk->sk_info_authunix == NULL) {
+		/* newly cached, keep the reference */
+		svsk->sk_info_authunix = ipm;
+		ipm = NULL;
+	}
+	spin_unlock_bh(&svsk->sk_defer_lock);
+	if (ipm)
 		cache_put(&ipm->h, &ip_map_cache);
 }