Based on the provided legal document, there is no explicit mention or discussion about the validity or invalidity of attachment before a civil court in relation to the specific land transfer restrictions under the relevant land laws. The document primarily focuses on the scope of the prohibition of transfers of assigned lands, the exceptions provided under the law, and the interpretation of mortgage and transfer provisions within the context of the Act.

The law emphasizes that transfers of assigned lands are generally null and void, and it specifies certain exemptions, such as mortgages in favor of specified government authorities, which are protected under the law. However, it does not explicitly state that attachment of assigned land before a civil court is barred or permissible.

Therefore, based on this document, it cannot be conclusively inferred that attachment before a civil court is barred. The law appears to restrict transfers and alienations of assigned land but does not explicitly mention the status or validity of attachment proceedings.

In conclusion, the document does not provide a clear ruling or prohibition regarding attachment before a civil court, and this issue may require further legal interpretation or reference to other laws or judicial pronouncements.