[aandrejevic] 67741: [NTVDM] - Make the Sda pointer point to the right place. - Fix a buffer overflow.

Author: aandrejevic
Date: Fri May 15 00:20:54 2015
New Revision: 67741

URL: http://svn.reactos.org/svn/reactos?rev=67741&view=rev
Log:
[NTVDM]
- Make the Sda pointer point to the right place.
- Fix a buffer overflow.

Modified:
    trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/dos.c

Modified: trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/dos.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/mvdm/ntvdm/dos/d...
==============================================================================
--- trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/dos.c	[iso-8859-1] (original)
+++ trunk/reactos/subsystems/mvdm/ntvdm/dos/dos32krnl/dos.c	[iso-8859-1] Fri May 15 00:20:54 2015
@@ -52,16 +52,22 @@

static BOOLEAN DosChangeDrive(BYTE Drive)
 {
-    WCHAR DirectoryPath[DOS_CMDLINE_LENGTH];
+    CHAR DirectoryPath[DOS_CMDLINE_LENGTH + 1];

/* Make sure the drive exists */
     if (Drive > (LastDrive - 'A')) return FALSE;

+    RtlZeroMemory(DirectoryPath, sizeof(DirectoryPath));
+
     /* Find the path to the new current directory */
-    swprintf(DirectoryPath, L"%c\%S", Drive + 'A', &CurrentDirectories[Drive * DOS_DIR_LENGTH]);
+    snprintf(DirectoryPath,
+             DOS_CMDLINE_LENGTH,
+             "%c\%s",
+             Drive + 'A',
+             &CurrentDirectories[Drive * DOS_DIR_LENGTH]);

/* Change the current directory of the process */
-    if (!SetCurrentDirectory(DirectoryPath)) return FALSE;
+    if (!SetCurrentDirectoryA(DirectoryPath)) return FALSE;

/* Set the current drive */
     CurrentDrive = Drive;
@@ -2013,7 +2019,7 @@
     }

/* Initialize the list of lists */
-    SysVars = (PDOS_SYSVARS)SEG_OFF_TO_PTR(DOS_DATA_SEGMENT, 0);
+    SysVars = (PDOS_SYSVARS)SEG_OFF_TO_PTR(DOS_DATA_SEGMENT, DOS_DATA_OFFSET(SysVars));
     RtlZeroMemory(SysVars, sizeof(DOS_SYSVARS));
     SysVars->FirstMcb = FIRST_MCB_SEGMENT;
     SysVars->FirstSft = MAKELONG(DOS_DATA_OFFSET(Sft), DOS_DATA_SEGMENT);
@@ -2034,7 +2040,7 @@
                   sizeof(NullDriverRoutine));

/* Initialize the swappable data area */
-    Sda = (PDOS_SDA)SEG_OFF_TO_PTR(DOS_DATA_SEGMENT, sizeof(DOS_SYSVARS));
+    Sda = (PDOS_SDA)SEG_OFF_TO_PTR(DOS_DATA_SEGMENT, DOS_DATA_OFFSET(Sda));
     RtlZeroMemory(Sda, sizeof(DOS_SDA));

/* Set the current PSP to the system PSP */