Preheat the oven to 375 degrees F (190 degrees C).

Melt butter in a large saucepan over medium heat. Remove from heat, then stir in flour, oats, brown sugar, and salt until mixture resembles dry crumbs.

Press about 2/3 of the crumbs evenly into the bottom of a 9-inch square pan. Top with cherry pie filling and sprinkle with remaining crumb mixture.

Bake in the preheated oven until cherries are bubbling and top is golden brown, 40 to 45 minutes.