From: Star Zeng <star.zeng@intel.com>
Date: Mon, 21 Jul 2014 03:05:20 +0000 (+0000)
Subject: MdePkg BaseLib: Fix a corner case of Source and Destination overlap.
X-Git-Tag: edk2-stable201903~11328
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=d52b9d864efb0ba4b812538c45aef0b617bace39

MdePkg BaseLib: Fix a corner case of Source and Destination overlap.

The overlap may happen when the address of Destination in
UnicodeStrToAsciiStr() or Source in AsciiStrToUnicodeStr()
is not two bytes aligned.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15665 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/MdePkg/Library/BaseLib/String.c b/MdePkg/Library/BaseLib/String.c
index 227a0dc846..9505c5b21e 100644
--- a/MdePkg/Library/BaseLib/String.c
+++ b/MdePkg/Library/BaseLib/String.c
@@ -1,7 +1,7 @@
 /** @file
   Unicode and ASCII string primatives.
 
-  Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -1040,7 +1040,7 @@ UnicodeStrToAsciiStr (
   //
   // Source and Destination should not overlap
   //
-  ASSERT ((UINTN) ((CHAR16 *) Destination -  Source) > StrLen (Source));
+  ASSERT ((UINTN) (Destination - (CHAR8 *) Source) >= StrSize (Source));
   ASSERT ((UINTN) ((CHAR8 *) Source - Destination) > StrLen (Source));
 
 
@@ -2008,9 +2008,9 @@ AsciiStrToUnicodeStr (
   // Source and Destination should not overlap
   //
   ASSERT ((UINTN) ((CHAR8 *) Destination - Source) > AsciiStrLen (Source));
-  ASSERT ((UINTN) (Source - (CHAR8 *) Destination) > (AsciiStrLen (Source) * sizeof (CHAR16)));
+  ASSERT ((UINTN) (Source - (CHAR8 *) Destination) >= (AsciiStrSize (Source) * sizeof (CHAR16)));
+
 
- 
   ReturnValue = Destination;
   while (*Source != '\0') {
     *(Destination++) = (CHAR16) *(Source++);