diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 82fc179..4122f3833 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -115,6 +115,16 @@
 			return 0;
 		}
 
+	/* originating subsystem */
+	if (uevent_ops && uevent_ops->name)
+		subsystem = uevent_ops->name(kset, kobj);
+	else
+		subsystem = kobject_name(&kset->kobj);
+	if (!subsystem) {
+		pr_debug("unset subsytem caused the event to drop!\n");
+		return 0;
+	}
+
 	/* environment index */
 	envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
 	if (!envp)
@@ -134,12 +144,6 @@
 		goto exit;
 	}
 
-	/* originating subsystem */
-	if (uevent_ops && uevent_ops->name)
-		subsystem = uevent_ops->name(kset, kobj);
-	else
-		subsystem = kobject_name(&kset->kobj);
-
 	/* event environemnt for helper process only */
 	envp[i++] = "HOME=/";
 	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";