Backport 5224e979a1cbce1b015e81aa7761743f60357d73

Author: duke

src/java.base/share/classes/java/util/concurrent/SubmissionPublisher.java

@@ -1059,7 +1059,7 @@ static final class BufferedSubscription<T>
         final Subscriber<? super T> subscriber;
         final BiConsumer<? super Subscriber<? super T>, ? super Throwable> onNextHandler;
         Executor executor;                 // null on error
-        Thread waiter;                     // blocked producer thread
+        volatile Thread waiter;            // blocked producer thread
         Throwable pendingError;            // holds until onError issued
         BufferedSubscription<T> next;      // used only by publisher
         BufferedSubscription<T> nextRetry; // used only by publisher