[jimtabor] 44902: [Win32k] - Patch by Dan Kegel: Fix minor read buffer overrun in CombineRgn. http://bugs.winehq.org/show_bug.cgi?id=20851 - When locking and unlocking regions, use probe to check attribute space first before read or write access.

Author: jimtabor
Date: Sun Jan  3 01:05:15 2010
New Revision: 44902

URL: http://svn.reactos.org/svn/reactos?rev=44902&view=rev
Log:
[Win32k]
- Patch by Dan Kegel: Fix minor read buffer overrun in CombineRgn.
http://bugs.winehq.org/show_bug.cgi?id=20851
- When locking and unlocking regions, use probe to check attribute space first before read
or write access.

Modified:
    trunk/reactos/subsystems/win32/win32k/objects/gdiobj.c
    trunk/reactos/subsystems/win32/win32k/objects/region.c

Modified: trunk/reactos/subsystems/win32/win32k/objects/gdiobj.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/win32k/ob…
==============================================================================
--- trunk/reactos/subsystems/win32/win32k/objects/gdiobj.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/win32k/objects/gdiobj.c [iso-8859-1] Sun Jan  3
01:05:15 2010
@@ -750,7 +750,12 @@
              {
                 return TRUE;
              }
-             if (pAttr) FreeObjectAttr(pAttr);
+             if (pAttr)
+             {
+                KeEnterCriticalRegion();
+                FreeObjectAttr(pAttr);
+                KeLeaveCriticalRegion();
+             }
              break;
 
           case GDI_OBJECT_TYPE_DC:

Modified: trunk/reactos/subsystems/win32/win32k/objects/region.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/win32k/ob…
==============================================================================
--- trunk/reactos/subsystems/win32/win32k/objects/region.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/win32k/objects/region.c [iso-8859-1] Sun Jan  3
01:05:15 2010
@@ -1650,7 +1650,8 @@
                 pNextRect++;
             }
             r1++;
-            left = r1->left;
+            if (r1 != r1End)
+                left = r1->left;
         }
     }
 
@@ -2062,9 +2063,11 @@
         }
     }
 
+    KeEnterCriticalRegion();
     Index = GDI_HANDLE_GET_INDEX(hReg);
     Entry = &GdiHandleTable->Entries[Index];
     Entry->UserData = AllocateObjectAttr();
+    KeLeaveCriticalRegion();
 
     EMPTY_REGION(pReg);
     pReg->rdh.dwSize = sizeof(RGNDATAHEADER);
@@ -2081,22 +2084,26 @@
   INT Index;
   PGDI_TABLE_ENTRY Entry;
   PROSRGNDATA pRgn;
-  PRGN_ATTR pRgn_Attr;
+  PRGN_ATTR pRgn_Attr;  
 
   pRgn = REGION_LockRgn(hRgn);
 
   if (pRgn)
   {
+     KeEnterCriticalRegion();
      Index = GDI_HANDLE_GET_INDEX(hRgn);
      Entry = &GdiHandleTable->Entries[Index];
-
      pRgn_Attr = Entry->UserData;
+     KeLeaveCriticalRegion();
 
      if (pRgn_Attr)
      {
         _SEH2_TRY
         {
-           if ( pRgn_Attr->AttrFlags & (ATTR_RGN_VALID|ATTR_RGN_DIRTY) )
+           ProbeForWrite(pRgn_Attr, sizeof(RGN_ATTR), 1);
+
+           if ( !(pRgn_Attr->AttrFlags & ATTR_CACHED) &&
+                 pRgn_Attr->AttrFlags & (ATTR_RGN_VALID|ATTR_RGN_DIRTY) )
            {
               switch (pRgn_Attr->Flags)
               {
@@ -2142,15 +2149,18 @@
 
   if (pRgn)
   {
+     KeEnterCriticalRegion();
      Index = GDI_HANDLE_GET_INDEX(pRgn->BaseObject.hHmgr);
      Entry = &GdiHandleTable->Entries[Index];
-
      pRgn_Attr = Entry->UserData;
-
-     _SEH2_TRY
+     KeLeaveCriticalRegion();
+
+     if ( pRgn_Attr )
      {
-        if ( pRgn_Attr )
-        {
+        _SEH2_TRY
+        {
+           ProbeForWrite(pRgn_Attr, sizeof(RGN_ATTR), 1);
+
            if ( pRgn_Attr->AttrFlags & ATTR_RGN_VALID )
            {
               pRgn_Attr->Flags = REGION_Complexity( pRgn );
@@ -2160,11 +2170,11 @@
               pRgn_Attr->Rect.bottom = pRgn->rdh.rcBound.bottom;
            }
         }
+        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+        {
+        }
+        _SEH2_END;
      }
-     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
-     {
-     }
-     _SEH2_END;
   }
   REGION_UnlockRgn(pRgn);
 }