From a5e2945149f7bda796fdfa22b6b6cbf89e40f04f Mon Sep 17 00:00:00 2001
From: Johannes Anderwald <johannes.anderwald@reactos.org>
Date: Wed, 1 Jul 2015 07:39:35 +0000
Subject: [PATCH] [PORTCLS] - check if there are enough irp stack locations

svn path=/trunk/; revision=68328
---
 reactos/drivers/wdm/audio/backpln/portcls/irp.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/reactos/drivers/wdm/audio/backpln/portcls/irp.cpp b/reactos/drivers/wdm/audio/backpln/portcls/irp.cpp
index 2cd09818ff7..bb535ed204c 100644
--- a/reactos/drivers/wdm/audio/backpln/portcls/irp.cpp
+++ b/reactos/drivers/wdm/audio/backpln/portcls/irp.cpp
@@ -548,7 +548,11 @@ PcForwardIrpSynchronous(
     // initialize the notification event
     KeInitializeEvent(&Event, NotificationEvent, FALSE);
 
-    IoCopyCurrentIrpStackLocationToNext(Irp);
+    // are there enough irp stack locations
+    if (Irp->CurrentLocation < Irp->StackCount + 1)
+    {
+        IoCopyCurrentIrpStackLocationToNext(Irp);
+    }
 
     IoSetCompletionRoutine(Irp, CompletionRoutine, (PVOID)&Event, TRUE, TRUE, TRUE);