[hbelusca] 66036: [FREELDR]: Addendum to PXE r66034: don't read after Path buffer validity.

Author: hbelusca
Date: Tue Jan 13 23:19:21 2015
New Revision: 66036

URL: http://svn.reactos.org/svn/reactos?rev=66036&view=rev
Log:
[FREELDR]: Addendum to PXE r66034: don't read after Path buffer validity.

Modified:
    trunk/reactos/boot/freeldr/freeldr/fs/pxe.c

Modified: trunk/reactos/boot/freeldr/freeldr/fs/pxe.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/boot/freeldr/freeldr/fs/pxe...
==============================================================================
--- trunk/reactos/boot/freeldr/freeldr/fs/pxe.c	[iso-8859-1] (original)
+++ trunk/reactos/boot/freeldr/freeldr/fs/pxe.c	[iso-8859-1] Tue Jan 13 23:19:21 2015
@@ -142,7 +142,7 @@
     if (_OpenFile == NO_FILE || FileId != _OpenFile)
         return EBADF;

-    RtlZeroMemory(Information, sizeof(FILEINFORMATION));
+    RtlZeroMemory(Information, sizeof(*Information));
     Information->EndingAddress.LowPart = _FileSize;
     Information->CurrentAddress.LowPart = _FilePosition;

@@ -153,22 +153,27 @@
 {
     t_PXENV_TFTP_GET_FSIZE sizeData;
     t_PXENV_TFTP_OPEN openData;
-    ULONG i;
+    SIZE_T PathLen, i;

if (_OpenFile != NO_FILE)
         return EIO;
     if (OpenMode != OpenReadOnly)
         return EACCES;

-    for (i = 0; i < sizeof(_OpenFileName) - 1; i++)
+    /* Retrieve the path length without NULL terminator */
+    PathLen = (Path ? min(strlen(Path), sizeof(_OpenFileName) - 1) : 0);
+
+    /* Zero out the file name */
+    RtlZeroMemory(_OpenFileName, sizeof(_OpenFileName));
+
+    /* Lowercase the path and always use slashes as separators */
+    for (i = 0; i < PathLen; i++)
     {
         if (Path[i] == '\')
             _OpenFileName[i] = '/';
         else
             _OpenFileName[i] = tolower(Path[i]);
     }
-    while (i < sizeof(_OpenFileName))
-        _OpenFileName[i++] = '\0';

RtlZeroMemory(&sizeData, sizeof(sizeData));
     sizeData.ServerIPAddress = _ServerIP;
@@ -183,7 +188,7 @@
     if (_FileSize < 1024 * 1024)
     {
         _CachedFile = FrLdrTempAlloc(_FileSize, TAG_PXE_FILE);
-        // Don't check for allocation failure, we support _CachedFile = NULL
+        // Don't check for allocation failure, we support _CachedFile == NULL
     }
     _CachedLength = 0;