CONTROLLER AND CONTROL METHOD FOR INTERNAL COMBUSTION ENGINE

A blow-by gas treating device discharges blow-by gas into intake air. A controller selects and executes one of a fuel cutoff process and a fuel introduction process when stopping combustion in a cylinder under a situation in which a crankshaft of the internal combustion engine is rotating. An injection valve controlling section controls a fuel injection valve to regulate a fuel injection amount in a period in which the combustion in the cylinder is stopped under the situation in which the crankshaft is rotating. The injection valve controlling section decreases the fuel injection amount from the fuel injection valve as an oil temperature that is the temperature of engine oil increases.