Changing models makes texture bug when breaking

I was trying to get different textures to different sides of planks but whenever I break or walk over them I get a texture bug, I'm on 1.8.

this is assets\minecraft\models\block\oak_planks

{
"parent": "block/cube_all",
"textures": {
"up": "blocks/planks_oak_top", "down": "blocks/planks_oak_top", "north": "blocks/planks_oak", "south": "blocks/planks_oak", "west": "blocks/planks_oak", "east": "blocks/planks_oak"
}
}