Check values before looping (#104273)

* check values before looping, if condition not met, send an error message

Author: mikelle-rogers

src/coreclr/pal/src/map/map.cpp

@@ -1587,23 +1587,31 @@ static PAL_ERROR MAPGrowLocalFile( INT UnixFD, off_t NewSize )
         }
 
         memset( buf, 0, BUFFER_SIZE );
-
-        for ( x = 0; x < NewSize - OrigSize - BUFFER_SIZE; x += BUFFER_SIZE )
+        if (NewSize - OrigSize - BUFFER_SIZE >= 0 && BUFFER_SIZE > 0)
         {
-            if ( write( UnixFD, (LPVOID)buf, BUFFER_SIZE ) == -1 )
+            for ( x = 0; x < NewSize - OrigSize - BUFFER_SIZE; x += BUFFER_SIZE )
             {
-                ERROR( "Unable to grow the file. Reason=%s\n", strerror( errno ) );
-                if((errno == ENOSPC) || (errno == EDQUOT))
+                if ( write( UnixFD, (LPVOID)buf, BUFFER_SIZE ) == -1 )
                 {
-                    palError = ERROR_DISK_FULL;
-                }
-                else
-                {
-                    palError = ERROR_INTERNAL_ERROR;
+                    ERROR( "Unable to grow the file. Reason=%s\n", strerror( errno ) );
+                    if((errno == ENOSPC) || (errno == EDQUOT))
+                    {
+                        palError = ERROR_DISK_FULL;
+                    }
+                    else
+                    {
+                        palError = ERROR_INTERNAL_ERROR;
+                    }
+                    goto done;
                 }
-                goto done;
             }
         }
+        else
+        {
+            //This will be an infinite loop because it did not pass the check.
+            palError = ERROR_INTERNAL_ERROR;
+            goto done;
+        }
         /* Catch any left overs. */
         if ( x != NewSize )
         {