diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 981a07f5967e5d2c63a8cfc9a833e458635ac460..4affc6e455113344e8eaf8c75449ef8f0f614e27 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2846,7 +2846,9 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 	switch (mode) {
 	case MPOL_PREFERRED:
 		/*
-		 * Insist on a nodelist of one node only
+		 * Insist on a nodelist of one node only, although later
+		 * we use first_node(nodes) to grab a single node, so here
+		 * nodelist (or nodes) cannot be empty.
 		 */
 		if (nodelist) {
 			char *rest = nodelist;
@@ -2854,6 +2856,8 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 				rest++;
 			if (*rest)
 				goto out;
+			if (nodes_empty(nodes))
+				goto out;
 		}
 		break;
 	case MPOL_INTERLEAVE: