Willian Jose gave Socieded, who dropped off the top spot after Wednesday’s game, an early lead when he tapped in Cristian Portu’s cross midway through the first half.
But Barcelona responded quickly as Alba curled a shot into the top corner before setting up De Jong just before halftime following a VAR review.
“We were intense, we put them under a lot of pressure and we ran ourselves into the ground.”
“Real Sociedad are excellent on the ball but we kept robbing it off them, we pressed them so well. It was an open game because our opponents know how to play very well but the game belonged to us and it was a deserved triumph.”
Barcelona next faces Valencia on Saturday, while Sociedad travels to Levante, a side which has gone nearly four weeks without a win.