[greatlrd] 49991: fix video memory lenght issue in VBEVideoShareVideoMemmory but few case itcan still map wrong range (outside the video ram)

Author: greatlrd
Date: Thu Dec  9 07:38:52 2010
New Revision: 49991

URL: http://svn.reactos.org/svn/reactos?rev=49991&view=rev
Log:
fix video memory lenght issue in VBEVideoShareVideoMemmory
but few case itcan still map wrong range (outside the video ram)

Modified:
    branches/reactx/reactos/drivers/video/miniport/vbe/vbemp.c

Modified: branches/reactx/reactos/drivers/video/miniport/vbe/vbemp.c
URL:
http://svn.reactos.org/svn/reactos/branches/reactx/reactos/drivers/video/mi…
==============================================================================
--- branches/reactx/reactos/drivers/video/miniport/vbe/vbemp.c [iso-8859-1] (original)
+++ branches/reactx/reactos/drivers/video/miniport/vbe/vbemp.c [iso-8859-1] Thu Dec  9
07:38:52 2010
@@ -868,28 +868,31 @@
     ULONG sharedViewSize;
     BOOLEAN retvalue;
     ULONG inIoSpace; 
-    
+
     /* in ms ddk xp it have two flag that are use full for us here 
        VIDEO_MEMORY_SPACE_USER_MODE or VIDEO_MEMORY_SPACE_P6CACHE
        the ddk say VIDEO_MEMORY_SPACE_P6CACHE does not care if it
        user mode or kmode memory. But we want be 100% sure it is
        vitual user mode memory adddress we mappin from kmode video memmory.
      */
-    inIoSpace = VIDEO_MEMORY_SPACE_USER_MODE;
-
-    if (DeviceExtension->ModeInfo[DeviceExtension->CurrentMode].ModeAttributes
& VBE_MODEATTR_LINEAR)
+
+    if ( ((DeviceExtension->ModeInfo[DeviceExtension->CurrentMode].ModeAttributes
& VBE_MODEATTR_LINEAR) != VBE_MODEATTR_LINEAR) ||
+         (pShareMemory->ViewOffset > VBEDeviceExtension->VbeInfo.TotalMemory)
||
+         ((pShareMemory->ViewOffset + pShareMemory->ViewSize) >
VBEDeviceExtension->VbeInfo.TotalMemory) )
+    {
+        retvalue = FALSE;
+    }
+    else
     {
         StatusBlock->Information = sizeof(VIDEO_SHARE_MEMORY_INFORMATION);
-
-        /* FIXME calc see we do not go over the video memory size */
-
         virtualAddress = pShareMemory->ProcessHandle;
         sharedViewSize = pShareMemory->ViewSize;
 
         shareAddress.QuadPart =
DeviceExtension->ModeInfo[DeviceExtension->CurrentMode].PhysBasePtr;
 
-        /* we iggnore the ViewOffset */
-
+        /* FIXME we iggnore the ViewOffset */
+
+        inIoSpace = VIDEO_MEMORY_SPACE_USER_MODE;
         StatusBlock->Status  = VideoPortMapMemory(  DeviceExtension,
                                                     shareAddress,
                                                     &sharedViewSize,
@@ -907,12 +910,8 @@
         {
             retvalue = FALSE;
         }
-        
     }
-    else
-    {
-        retvalue = FALSE;
-    }
+
 
     return retvalue;
 }