diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 5f5fe63a3d1c..7ba0840fc3b5 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1093,9 +1093,9 @@ struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
 		/*
 		 * Process closes window during exit. In the case of
 		 * multithread application, the child thread can open
-		 * window and can exit without closing it. Expects parent
-		 * thread to use and close the window. So do not need
-		 * to take pid reference for parent thread.
+		 * window and can exit without closing it. so takes tgid
+		 * reference until window closed to make sure tgid is not
+		 * reused.
 		 */
 		txwin->tgid = find_get_pid(task_tgid_vnr(current));
 		/*
@@ -1339,8 +1339,9 @@ int vas_win_close(struct vas_window *window)
 	/* if send window, drop reference to matching receive window */
 	if (window->tx_win) {
 		if (window->user_win) {
-			/* Drop references to pid and mm */
+			/* Drop references to pid. tgid and mm */
 			put_pid(window->pid);
+			put_pid(window->tgid);
 			if (window->mm) {
 				mm_context_remove_vas_window(window->mm);
 				mmdrop(window->mm);