Index: drivers/filesystems/ffs/src/except.c
===================================================================
--- drivers/filesystems/ffs/src/except.c	(revision 71918)
+++ drivers/filesystems/ffs/src/except.c	(working copy)
@@ -72,9 +72,9 @@
 	//  request as being able to wait, and neither write through nor on
 	//  removable media if we aren't posting it.
 	//
+    if (IrpContext)
+        SetFlag(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT);
 
-	SetFlag(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT);
-
 	if (FsRtlIsNtstatusExpected(ExceptionCode))
 	{
 		//