net:l2tp.sh failure with lunar:linux 6.2

[Andrea Righi]

[Impact]

Kernel selftest net:l2tp.sh is failing with the latest lunar/linux 6.2 kernel, the error is the following:

  RTNETLINK answers: Protocol not supported

Using `bash -x` we can see that the last command executed is the following:

  ip -netns host-1 l2tp add tunnel tunnel_id 1041 peer_tunnel_id 1042 encap ip local 10.1.1.1 remote 10.1.2.1

[Test case]

From the kernel source directory run:

 $ sudo ./tools/testing/selftests/net/l2tp.sh

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 2013014

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Andrea Righi (arighi)]

After explicitly loading the modules the test completes correctly:

sudo modprobe l2tp_ip6
sudo modprobe l2tp_ip
sudo modprobe l2tp_eth

$ sudo ./tools/testing/selftests/net/l2tp.sh
TEST: IPv4 basic L2TP tunnel [ OK ]
TEST: IPv4 route through L2TP tunnel [ OK ]
TEST: IPv6 basic L2TP tunnel [ OK ]
TEST: IPv6 route through L2TP tunnel [ OK ]
TEST: IPv4 basic L2TP tunnel - with IPsec [ OK ]
TEST: IPv4 route through L2TP tunnel - with IPsec [ OK ]
TEST: IPv6 basic L2TP tunnel - with IPsec [ OK ]
TEST: IPv6 route through L2TP tunnel - with IPsec [ OK ]
TEST: IPv4 basic L2TP tunnel [ OK ]
TEST: IPv4 route through L2TP tunnel [ OK ]
TEST: IPv6 basic L2TP tunnel - with IPsec [ OK ]
TEST: IPv6 route through L2TP tunnel - with IPsec [ OK ]
TEST: IPv4 basic L2TP tunnel - after IPsec teardown [ OK ]
TEST: IPv4 route through L2TP tunnel - after IPsec teardown [ OK ]
TEST: IPv6 basic L2TP tunnel - after IPsec teardown [ OK ]
TEST: IPv6 route through L2TP tunnel - after IPsec teardown [ OK ]

Tests passed: 16
Tests failed: 0

[Andrea Righi (arighi)]

It looks like the problem here is that with 6.2 (in lunar) the l2tp modules are not loaded automatically, in 5.19 (kinetic) they were loaded automatically without an explicit modprobe.

More exactly the module that is not loaded automatically is l2tp_ip6.

[Andrea Righi (arighi)]

Upstream commit 65b32f801bfb ("uapi: move IPPROTO_L2TP to in.h") introduced this regression.

With that commit we moved IPPROTO_L2TP from a define to an enum, breaking the macro that generates the module alias. This is the reason why the modules are not loaded automatically anymore.

Upstream thread: https://lore.kernel.org/lkml/ZCQt7hmodtUaBlCP@righiandr-XPS-13-7390/T/#m0492adf022ca40667f692088cf11f4284ac6fc52

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 6.2.0-20.20

---------------
linux (6.2.0-20.20) lunar; urgency=medium

  * lunar/linux: 6.2.0-20.20 -proposed tracker (LP: #2015429)

  * Packaging resync (LP: #1786013)
    - debian/dkms-versions -- update from kernel-versions (main/master)

  * FTBFS with different dkms or when makeflags are set (LP: #2015361)
    - [Packaging] FTBFS with different dkms or when makeflags are set

  * expoline.o is packaged unconditionally for s390x (LP: #2013209)
    - [Packaging] Copy expoline.o only when produced by the build

  * net:l2tp.sh failure with lunar:linux 6.2 (LP: #2013014)
    - SAUCE: l2tp: generate correct module alias strings

  * Miscellaneous Ubuntu changes
    - [Packaging] annotations: prevent duplicate include lines

 -- Andrea Righi <email address hidden> Thu, 06 Apr 2023 08:33:14 +0200

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-raspi/6.2.0-1005.7 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-lunar' to 'verification-done-lunar'. If the problem still exists, change the tag 'verification-needed-lunar' to 'verification-failed-lunar'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-riscv/6.2.0-23.23.1 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-lunar' to 'verification-done-lunar'. If the problem still exists, change the tag 'verification-needed-lunar' to 'verification-failed-lunar'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-azure/6.2.0-1009.9 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-lunar' to 'verification-done-lunar'. If the problem still exists, change the tag 'verification-needed-lunar' to 'verification-failed-lunar'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!