The Raiders signed Smith off the Saints' practice squad Thursday, Greg Auman of Fox Sports reports.
Smith was released by the Saints on Tuesday, Nick Underhill of NewOrleans.Football reports.
Smith signed with the Saints on Thursday, Jordan Schultz reports.
Smith played in 13 games this season, racking up 88 tackles (46 solo), one sack and a recovered fumble.
Smith tallied nine tackles (five solo) during Sunday's 38-10 win over the Colts.
Smith tallied 10 tackles (three solo), including one sack, in Saturday's loss to the Vikings.
Smith recorded nine tackles (four solo) Sunday in a Week 15 20-12 win over Washington.
Smith had nine tackles (seven solo) in Sunday's 48-22 loss to the Eagles.
Smith logged 10 tackles (seven solo) during the Giants' 28-20 loss to Dallas on Thursday.
Smith signed a contract with the Giants on Saturday, Dan Salomone of the Giants' official site reports.