net test in ubuntu_kernel_selftest failed on s390x KVM

Verified with the testing tool in the upstream kernel, this issue can be reproduced with it.

 not ok 1..4 selftests: reuseport_dualstack [FAIL]
 selftests: reuseaddr_conflict

Please find the complete test report here:
https://pastebin.ubuntu.com/p/3sRh6Nr9KR/

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-43-generic 4.15.0-43.46
ProcVersionSignature: Ubuntu 4.15.0-43.46-generic 4.15.18
Uname: Linux 4.15.0-43-generic s390x
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access '/dev/snd/': No such file or directory
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay': 'aplay'
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: s390x
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord': 'arecord'
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Date: Mon Dec 24 03:10:49 2018
HibernationDevice: RESUME=UUID=caaee9b2-6bc1-4c8e-b26c-69038c092091
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig': 'iwconfig'
Lspci:

Lsusb: Error: command ['lsusb'] failed with exit code 1:
PciMultimedia:

ProcFB: Error: [Errno 2] No such file or directory: '/proc/fb'
ProcKernelCmdLine: root=UUID=c7d7bbcb-a039-4ead-abfe-7672dea0add4 crashkernel=196M
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-43-generic N/A
 linux-backports-modules-4.15.0-43-generic N/A
 linux-firmware 1.173.3
RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)