Comment 0 for bug 1887661

Issue found on B-5.4 oracle 5.4.0-1021.21~18.04.1

The pmtu.sh test in net from ubuntu_kernel_selftests will be marked as failed even there is no obvious failure message from the test:
$ sudo ./pmtu.sh
TEST: ipv4: PMTU exceptions [ OK ]
TEST: ipv6: PMTU exceptions [ OK ]
  vxlan4 not supported
TEST: IPv4 over vxlan4: PMTU exceptions [SKIP]
  vxlan4 not supported
TEST: IPv6 over vxlan4: PMTU exceptions [SKIP]
TEST: IPv4 over vxlan6: PMTU exceptions [ OK ]
TEST: IPv6 over vxlan6: PMTU exceptions [ OK ]
  geneve4 not supported
TEST: IPv4 over geneve4: PMTU exceptions [SKIP]
  geneve4 not supported
TEST: IPv6 over geneve4: PMTU exceptions [SKIP]
TEST: IPv4 over geneve6: PMTU exceptions [ OK ]
TEST: IPv6 over geneve6: PMTU exceptions [ OK ]
TEST: IPv4 over fou4: PMTU exceptions [ OK ]
TEST: IPv6 over fou4: PMTU exceptions [ OK ]
TEST: IPv4 over fou6: PMTU exceptions [ OK ]
TEST: IPv6 over fou6: PMTU exceptions [ OK ]
TEST: IPv4 over gue4: PMTU exceptions [ OK ]
TEST: IPv6 over gue4: PMTU exceptions [ OK ]
TEST: IPv4 over gue6: PMTU exceptions [ OK ]
TEST: IPv6 over gue6: PMTU exceptions [ OK ]
TEST: vti6: PMTU exceptions [ OK ]
TEST: vti4: PMTU exceptions [ OK ]
TEST: vti4: default MTU assignment [ OK ]
TEST: vti6: default MTU assignment [ OK ]
TEST: vti4: MTU setting on link creation [ OK ]
TEST: vti6: MTU setting on link creation [ OK ]
TEST: vti6: MTU changes on link changes [ OK ]
  vxlan4 not supported
TEST: ipv4: cleanup of cached exceptions [SKIP]
TEST: ipv6: cleanup of cached exceptions [ OK ]
TEST: ipv4: list and flush cached exceptions [ OK ]
TEST: ipv6: list and flush cached exceptions [ OK ]
ubuntu@selfprovisioned-phlin-b-5-4-net:~/autotest/client/tmp/ubuntu_kernel_selftests/src/linux/tools/testing/selftests/net$ echo $?
1

Probably a test case issue.

This is not a regression as I can reproduce this on Bionic 5.4.0-1019-oracle as well

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-5.4.0-1019-oracle 5.4.0-1019.19~18.04.1
ProcVersionSignature: User Name 5.4.0-1019.19~18.04.1-oracle 5.4.44
Uname: Linux 5.4.0-1019-oracle x86_64
ApportVersion: 2.20.9-0ubuntu7.9
Architecture: amd64
Date: Wed Jul 15 11:28:29 2020
SourcePackage: linux-signed-oracle-5.4
UpgradeStatus: No upgrade log present (probably fresh install)