The 34-year-old woman told investigators she hit the boy with the rolling pin because she couldn't go online, RIA Novosti reported.
She told authorities she dismembered her son's body and hid it in a cellar. The woman's name and date of the attack were not released.
Investigators said the boy died of stab wounds and not blunt trauma, however, the Russian news agency said.
The woman was sentenced Monday to 12 years and 10 months in a penal colony.