This could work for Layer Masks, but not Vector Masks.

// 2012; use it at your own risk;
#target photoshop
if (app.documents.length > 0) {
linkLayerMasks(app.activeDocument)
};
////// link all layer masks //////
function linkLayerMasks (theParent) {
          for (var m = theParent.layers.length - 1; m >= 0;m--) {
                    var theLayer = theParent.layers[m];
                    app.activeDocument.activeLayer = theLayer;
                    var ref = new ActionReference();
                    ref.putEnumerated( charIDToTypeID("Lyr "), charIDToTypeID("Ordn"), charIDToTypeID("Trgt") ); 
                    var layerDesc = executeActionGet(ref);
                    var layerMaskLinked = layerDesc.getBoolean(layerDesc.getKey(10));
// link if unlinked;
                    if (layerMaskLinked == false) {
                              var idsetd = charIDToTypeID( "setd" );
                                        var desc4 = new ActionDescriptor();
                                        var idnull = charIDToTypeID( "null" );
                                                  var ref2 = new ActionReference();
                                                  var idLyr = charIDToTypeID( "Lyr " );
                                                  var idOrdn = charIDToTypeID( "Ordn" );
                                                  var idTrgt = charIDToTypeID( "Trgt" );
                                                  ref2.putEnumerated( idLyr, idOrdn, idTrgt );
                                        desc4.putReference( idnull, ref2 );
                                        var idT = charIDToTypeID( "T   " );
                                                  var desc5 = new ActionDescriptor();
                                                  var idUsrs = charIDToTypeID( "Usrs" );
                                                  desc5.putBoolean( idUsrs, true );
                                        var idLyr = charIDToTypeID( "Lyr " );
                                        desc4.putObject( idT, idLyr, desc5 );
                              executeAction( idsetd, desc4, DialogModes.NO );
                              };
// apply the function to layersets;
                    if (theLayer.typename == "ArtLayer") {}
                    else {
                              linkLayerMasks(theLayer)
                              }
                    }
          };

Here is another version, this does not open any layersets, and should be faster as it references the layers rather than making active each one.

#target photoshop
app.bringToFront();
main();
function main(){
if(!documents.length) return;
linkLayers();
}
function linkLayers(){ 
   var ref = new ActionReference(); 
   ref.putEnumerated( charIDToTypeID('Dcmn'), charIDToTypeID('Ordn'), charIDToTypeID('Trgt') ); 
   var count = executeActionGet(ref).getInteger(charIDToTypeID('NmbL')) +1; 
   var Names=[];
try{
    activeDocument.backgroundLayer;
var i = 0; }catch(e){ var i = 1; };
   for(i;i<count;i++){ 
       if(i == 0) continue;
        ref = new ActionReference(); 
        ref.putIndex( charIDToTypeID( 'Lyr ' ), i );
        var desc = executeActionGet(ref);
        var layerName = desc.getString(charIDToTypeID( 'Nm  ' ));
        var Id = desc.getInteger(stringIDToTypeID( 'layerID' ));
        if(layerName.match(/^<\/Layer group/) ) continue;
        if(desc.hasKey(charIDToTypeID("UsrM"))) link(i);
            }
};
function link(idx){
var desc = new ActionDescriptor(); 
var ref = new ActionReference(); 
ref.putIndex( charIDToTypeID( "Lyr " ), idx ); 
desc.putReference( charIDToTypeID('null'), ref ); 
var desc2 = new ActionDescriptor(); 
desc2.putBoolean( charIDToTypeID('Usrs'), true); 
desc.putObject( charIDToTypeID('T   '), charIDToTypeID('Lyr '), desc2 ); 
executeAction( charIDToTypeID('setd'), desc, DialogModes.NO ); 
};