The BPF virtual machine within the kernel has seen a great deal of work
over the last few years; as that has happened, its use has expanded to many
different kernel subsystems. One of the objectives of that work in the
past has been
to make it safe to allow unprivileged users to load at least some types of
BPF programs into the kernel. A recent discussion has made it clear,
though, that the goal of opening up BPF to unprivileged users has been
abandoned as unachievable, and that further work in that direction will not
be accepted by the BPF maintainer.

Source: LWN.net – [$] Reconsidering unprivileged BPF