From: qhuang8 <qhuang8@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Wed, 23 Dec 2009 01:50:10 +0000 (+0000)
Subject: Fix a bug in MdePkg BaseLib: StrnCat() and AsciiStrnCat() should NULL terminated... 
X-Git-Tag: edk2-stable201903~16733
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=8f635c36ad1059a064c747fd1f0e38814e7e7c29;p=mirror_edk2.git

Fix a bug in MdePkg BaseLib: StrnCat() and AsciiStrnCat() should NULL terminated the final destination string when Length is equal to the length of Source string

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9588 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/MdePkg/Library/BaseLib/String.c b/MdePkg/Library/BaseLib/String.c
index 31ea36de41..afbad1d4e3 100644
--- a/MdePkg/Library/BaseLib/String.c
+++ b/MdePkg/Library/BaseLib/String.c
@@ -425,7 +425,11 @@ StrnCat (
   IN      UINTN                     Length
   )
 {
-  StrnCpy (Destination + StrLen (Destination), Source, Length);
+  UINTN   DestinationLen;
+
+  DestinationLen = StrLen (Destination);
+  StrnCpy (Destination + DestinationLen, Source, Length);
+  Destination[DestinationLen + Length] = L'\0';
 
   //
   // Size of the resulting string should never be zero.
@@ -1566,7 +1570,11 @@ AsciiStrnCat (
   IN      UINTN                     Length
   )
 {
-  AsciiStrnCpy (Destination + AsciiStrLen (Destination), Source, Length);
+  UINTN   DestinationLen;
+
+  DestinationLen = AsciiStrLen (Destination);
+  AsciiStrnCpy (Destination + DestinationLen, Source, Length);
+  Destination[DestinationLen + Length] = '\0';
 
   //
   // Size of the resulting string should never be zero.