diff --git a/[refs] b/[refs]
index ddeb1a0be42a..536e339da863 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6003a93e7bf6c02f33c02976ff364785d4273295
+refs/heads/master: 8e31108b9f41069d55cb9b019ac8262c55fd2616
diff --git a/trunk/kernel/futex.c b/trunk/kernel/futex.c
index 5872e3507f35..5e71a6bf6f6b 100644
--- a/trunk/kernel/futex.c
+++ b/trunk/kernel/futex.c
@@ -270,7 +270,13 @@ static void wake_futex(struct futex_q *q)
 	/*
 	 * The waiting task can free the futex_q as soon as this is written,
 	 * without taking any locks.  This must come last.
+	 *
+	 * A memory barrier is required here to prevent the following store
+	 * to lock_ptr from getting ahead of the wakeup. Clearing the lock
+	 * at the end of wake_up_all() does not prevent this store from
+	 * moving.
 	 */
+	wmb();
 	q->lock_ptr = NULL;
 }