Hello,

I'm unable to load the wireguard kernel module on Debian Sid or Debian Buster. (4.19.0-5-amd64 kernel)
(Debian buster is scheduled to be promoted to stable in a couple of weeks)

root@buster:~# modprobe wireguard
modprobe: ERROR: could not insert 'wireguard': Invalid argument
root@buster:~# modinfo wireguard
filename: /lib/modules/4.19.0-5-amd64/updates/dkms/wireguard.ko
alias: net-pf-16-proto-16-family-wireguard
alias: rtnl-link-wireguard
version: 0.0.20190601
author: Jason A. Donenfeld <Jason@zx2c4.com>
description: WireGuard secure network tunnel
license: GPL v2
srcversion: 69000E9D4B2B253E97C189A
depends: udp_tunnel,ip6_udp_tunnel
retpoline: Y
name: wireguard
vermagic: 4.19.0-5-amd64 SMP mod_unload modversions

The same version seems to work fine on Debian Stretch (4.9.0-9) or Fedora Core 30 (5.1.11-300)

The kernel ring throws a number of symbol version errors:

[...]
[ 97.450944] wireguard: loading out-of-tree module taints kernel.
[ 97.453335] wireguard: module verification failed: signature and/or required key missing - tainting kernel
[ 97.457727] wireguard: disagrees about version of symbol skb_put
[ 97.459772] wireguard: Unknown symbol skb_put (err -22)
[ 97.461555] wireguard: disagrees about version of symbol ip6_dst_hoplimit
[ 97.463609] wireguard: Unknown symbol ip6_dst_hoplimit (err -22)
[ 97.465590] wireguard: disagrees about version of symbol consume_skb
[ 97.467495] wireguard: Unknown symbol consume_skb (err -22)
[ 97.469326] wireguard: disagrees about version of symbol udp_sock_create4
[...]

I have tried both the apt package from debian unstable, as well as compile from source.

Any idea what could be going wrong? Is this a Debian kernel bug?
Thanks in advance,

Nils