What is the ruling on wiping over socks during ablution (wudu') in the Maliki school of thought, and what is the ruling on praying behind someone who performed ablution by wiping over his socks?

There are conditions for wiping over the khuffayn (leather slippers) and jawrabayn (socks). The Malikis added a condition that the outer and inner layers of the sock must be made of leather. If the conditions are met, the prayer is valid for the one who wiped over them and for those who follow him in prayer. However, if a condition is not met, the prayer becomes invalid due to the impurity of the ablution. This also applies to the follower if he is aware of his Imam's invalid ablution.