[tkreuzer] 63388: [NTOSKRNL] Fix ending address calculation for the commit path in NtAllocateVirtualMemory like done for the reserve path in r63356. Add a comment about a Windows kernel bug, which ...

Author: tkreuzer
Date: Tue May 20 21:11:43 2014
New Revision: 63388

URL: http://svn.reactos.org/svn/reactos?rev=63388&view=rev
Log:
[NTOSKRNL]
Fix ending address calculation for the commit path in NtAllocateVirtualMemory like done
for the reserve path in r63356. Add a comment about a Windows kernel bug, which we will
keep for now, until the implications are better determined.

Modified:
    trunk/reactos/ntoskrnl/mm/ARM3/virtual.c

Modified: trunk/reactos/ntoskrnl/mm/ARM3/virtual.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/virtual.c…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/virtual.c	[iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/ARM3/virtual.c	[iso-8859-1] Tue May 20 21:11:43 2014
@@ -4593,8 +4593,8 @@
     // on the user input, and then compute the actual region size once all the
     // alignments have been done.
     //
+    EndingAddress = (((ULONG_PTR)PBaseAddress + PRegionSize - 1) | (PAGE_SIZE - 1));
     StartingAddress = (ULONG_PTR)PAGE_ALIGN(PBaseAddress);
-    EndingAddress = (((ULONG_PTR)PBaseAddress + PRegionSize - 1) | (PAGE_SIZE - 1));
     PRegionSize = EndingAddress - StartingAddress + 1;
 
     //
@@ -4700,6 +4700,12 @@
         {
             //
             // Make sure it's okay to touch it
+            // Note: The Windows 2003 kernel has a bug here, passing the
+            // unaligned base address together with the aligned size,
+            // potentially covering a region larger than the actual allocation.
+            // Might be exposed through NtGdiCreateDIBSection w/ section handle
+            // For now we keep this behavior.
+            // TODO: analyze possible implications, create test case
             //
             Status = MiCheckSecuredVad(FoundVad,
                                        PBaseAddress,