diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 584866ed92f14751b00142ed7f27d5c1468eb577..5c41794617c64fa58da00156ded358b679a645cb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5021,9 +5021,12 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
 	buf = endp + 1;
 
 	cfd = simple_strtoul(buf, &endp, 10);
-	if ((*endp != ' ') && (*endp != '\0'))
+	if (*endp == '\0')
+		buf = endp;
+	else if (*endp == ' ')
+		buf = endp + 1;
+	else
 		return -EINVAL;
-	buf = endp + 1;
 
 	event = kzalloc(sizeof(*event), GFP_KERNEL);
 	if (!event)