[vmikayelyan] 72368: usb: hub: PDO: New checking in IsValidPDO() As child's parent FDO at any moment can receive surprise removal, Before being it should notify it's childs by setting their parents...

Author: vmikayelyan
Date: Fri Aug 19 15:34:48 2016
New Revision: 72368
URL: http://svn.reactos.org/svn/reactos?rev=72368&view=rev
Log:
usb: hub: PDO: New checking in IsValidPDO()
As child's parent FDO at any moment can receive surprise removal,
Before being it should notify it's childs by setting their parents to NULL.
So if we see PDO with parent==NULL then we can consider it as physically
removed, i.e. invalid.
Modified:
    branches/GSoC_2016/USB/drivers/usb/usbhub/pdo.c
Modified: branches/GSoC_2016/USB/drivers/usb/usbhub/pdo.c
URL:
http://svn.reactos.org/svn/reactos/branches/GSoC_2016/USB/drivers/usb/usbhu…
==============================================================================
--- branches/GSoC_2016/USB/drivers/usb/usbhub/pdo.c     [iso-8859-1] (original)
+++ branches/GSoC_2016/USB/drivers/usb/usbhub/pdo.c     [iso-8859-1] Fri Aug 19 15:34:48
2016
@@ -146,6 +146,11 @@
     ChildDeviceExtension = (PHUB_CHILDDEVICE_EXTENSION)DeviceObject->DeviceExtension;
     ASSERT(ChildDeviceExtension->Common.IsFDO == FALSE);
+
+    // This can happen when parent device was surprise removed.
+    if (ChildDeviceExtension->ParentDeviceObject == NULL)
+        return FALSE;
+
     HubDeviceExtension =
(PHUB_DEVICE_EXTENSION)ChildDeviceExtension->ParentDeviceObject->DeviceExtension;
     for(Index = 0; Index < USB_MAXCHILDREN; Index++)