[tfaber] 62591: [RTL] - Fix buffer overrun in RtlNumberOfSetBits

Author: tfaber
Date: Mon Mar 31 19:57:42 2014
New Revision: 62591

URL: http://svn.reactos.org/svn/reactos?rev=62591&view=rev
Log:
[RTL]
- Fix buffer overrun in RtlNumberOfSetBits

Modified:
    trunk/reactos/lib/rtl/bitmap.c

Modified: trunk/reactos/lib/rtl/bitmap.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/rtl/bitmap.c?rev=62591…
==============================================================================
--- trunk/reactos/lib/rtl/bitmap.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/rtl/bitmap.c	[iso-8859-1] Mon Mar 31 19:57:42 2014
@@ -467,8 +467,11 @@
         BitCount += BitCountTable[*Byte++];
     }
 
-    Shift = 8 - (BitMapHeader->SizeOfBitMap & 7);
-    BitCount += BitCountTable[((*Byte) << Shift) & 0xFF];
+    if (BitMapHeader->SizeOfBitMap & 7)
+    {
+        Shift = 8 - (BitMapHeader->SizeOfBitMap & 7);
+        BitCount += BitCountTable[((*Byte) << Shift) & 0xFF];
+    }
 
     return BitCount;
 }