Regression on Jammy's kernel 5.15 when creating ip6gre and vti6 tunnels

We noticed that some of Netplan's integration tests started to fail on Jammy. These tests will try to create ip6gre and vti6 virtual interfaces and systemd-networkd is failing to create them starting on kernel 5.15.0-83.92. As far as I can tell, kernel 5.15.0-82.91 is the last revision where it works. So, some change between 5.15.0-82.91 and 5.15.0-83.92 is causing this regression.

How to reproduce the issue:

# Launch a jammy cloud VM:

lxc launch images:ubuntu/jammy/cloud jammy --vm
lxc shell jammy

# Create a netplan file that creates 2 tunnels:

cat > /etc/netplan/10-tun.yaml <<EOF
network:
  renderer: networkd
  version: 2
  tunnels:
    tun0:
      mode: ip6gre
      local: fe80::1
      remote: 2001:dead:beef::2
    tun1:
      mode: vti6
      local: fe80::2
      remote: 2001:dead:beef::3
EOF

# Apply the configuration

netplan apply

# Check with "ip link" that both tun0 and tun1 *were not created* and check networkd for errors:

journalctl -u systemd-networkd

Sep 28 17:04:40 jammy systemd-networkd[360]: tun0: netdev could not be created: Invalid argument
Sep 28 17:04:40 jammy systemd-networkd[360]: tun1: netdev could not be created: Invalid argument

# Download, install and boot on kernel 5.15.0-82.91

wget http://ie.archive.ubuntu.com/ubuntu/pool/main/l/linux-signed/linux-image-5.15.0-82-generic_5.15.0-82.91_amd64.deb http://ie.archive.ubuntu.com/ubuntu/pool/main/l/linux/linux-modules-5.15.0-82-generic_5.15.0-82.91_amd64.deb

dpkg -i *.deb

grub-reboot '1>2' && reboot

# Check with "ip link" again that both tun0 and tun1 were created

# Reboot again to go back to the most recent kernel and check with "ip link" that both tun0 and tun1 were not created.
---
ProblemType: Bug
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 Sep 29 12:52 seq
 crw-rw---- 1 root audio 116, 33 Sep 29 12:52 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: [Errno 2] No such file or directory: 'fuser'
CRDA: N/A
CasperMD5CheckResult: unknown
CloudArchitecture: x86_64
CloudID: lxd
CloudName: lxd
CloudPlatform: lxd
CloudSubPlatform: LXD socket API v. 1.0 (/dev/lxd/sock)
DistroRelease: Ubuntu 22.04
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lspci: Error: [Errno 2] No such file or directory: 'lspci'
Lspci-vt: Error: [Errno 2] No such file or directory: 'lspci'
Lsusb: Error: [Errno 2] No such file or directory: 'lsusb'
Lsusb-t: Error: [Errno 2] No such file or directory: 'lsusb'
Lsusb-v: Error: [Errno 2] No such file or directory: 'lsusb'
MachineType: QEMU Standard PC (Q35 + ICH9, 2009)
Package: linux (not installed)
PciMultimedia:

ProcEnviron:
 TERM=screen-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 virtio_gpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.15.0-84-generic root=/dev/sda2 ro quiet splash console=tty1 console=ttyS0 vt.handoff=7
ProcVersionSignature: Ubuntu 5.15.0-84.93-generic 5.15.116
RelatedPackageVersions:
 linux-restricted-modules-5.15.0-84-generic N/A
 linux-backports-modules-5.15.0-84-generic N/A
 linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
Tags: jammy uec-images
Uname: Linux 5.15.0-84-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: N/A
_MarkForUpload: True
dmi.bios.date: 2/2/2022
dmi.bios.release: 0.0
dmi.bios.vendor: EDK II
dmi.bios.version: unknown
dmi.board.name: LXD
dmi.board.vendor: Canonical Ltd.
dmi.board.version: pc-q35-8.0
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: pc-q35-8.0
dmi.modalias: dmi:bvnEDKII:bvrunknown:bd2/2/2022:br0.0:svnQEMU:pnStandardPC(Q35+ICH9,2009):pvrpc-q35-8.0:rvnCanonicalLtd.:rnLXD:rvrpc-q35-8.0:cvnQEMU:ct1:cvrpc-q35-8.0:sku:
dmi.product.name: Standard PC (Q35 + ICH9, 2009)
dmi.product.version: pc-q35-8.0
dmi.sys.vendor: QEMU