The Raiders signed Smith off the Saints' practice squad Thursday, Greg Auman of Fox Sports reports.
The 28-year-old was the 34th overall pick in the 2016 NFL Draft and has started 69 of the 87 career games he's played in across six seasons with the Cowboys, Giants and Packers. Three Raiders linebackers -- Divine Deablo (ankle), Luke Masterson (concussion) and Robert Spillane (hand) -- didn't practice Wednesday.