Adding bpf to CONFIG_LSM in linux kernel

[roblabla]

Linux kernel since 5.7 allows to write eBPF programs which can be attached to LSM hooks. More details here:

https://www.kernel.org/doc/html/v5.9/bpf/bpf_lsm.html

There are already projects trying to leverage that

systemd with the restrict-fs feature
https://github.com/systemd/systemd/blob/main/src/core/bpf/restrict_fs/restrict-fs.bpf.c

https://github.com/linux-lock/bpflock

https://github.com/lockc-project/lockc

However, BPF LSM has to be enabled by adding bpf to CONFIG_LSM.
That was already done in:

Arch Linux

https://github.com/archlinux/svntogit-packages/blob/4615bb2493649ad6fa133f864f94cb95c824f361/trunk/config#L9963

Fedora

https://fedorapeople.org/cgit/thl/public_git/kernel.git/tree/kernel-x86_64-fedora.config?h=kernel-5.17.0-0.rc5.20220225git53ab78cd6d5a.106.vanilla.1.fc34&id=e661d91eb909e777a9d28425ef50fcc5ef7fa5ed#n3291

openSUSE

https://github.com/openSUSE/kernel-source/commit/c2c25b18721866d6211054f542987036ed6e0a50

Debian

https://salsa.debian.org/kernel-team/linux/-/blob/master/debian/config/config?ref_type=heads#L7713

RedHat

https://access.redhat.com/labs/rhcb/RHEL-8.9/kernel-4.18.0-513.18.1.el8/source/blob/redhat/configs/generic/CONFIG_LSM

Could we please enable BPF LSM in Ubuntu kernels as well? Without that change, users trying to play with the mentioned projects have to edit their /etc/default/grub to add bpf LSM.

[roblabla (roblabla)]

(This is reposting 1964941 which appears to have expired)

[Eric Sheridan (esheri3)]

Can Ubuntu please consider addressing this as a part of the upcoming 24 LTS release? The ability to leverage LSM based BPF programs on Ubuntu out-of-the-box (ie. without having to update grub and rebooting) opens the door to a growing ecosystem of security tooling. There are major computing environments for which the community cannot control things like Grub settings - such as the Ubuntu images used by Microsoft (via GitHub Actions, Azure Pipelines), GitLab (via Jobs), AWS (via vanilla EC2 instances), etc.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Eric Sheridan (esheri3)]

Joseph - thanks for looking into this. Please let me know if I can be of assistance. I'd be happy to test out the corresponding changes on my end. Just let me know - thank you!!

[Joseph Salisbury (jsalisbury)]

Thanks, Eric! I'm going to build some test kernels and will post them shortly.

[Eric Sheridan (esheri3)]

Hi Joseph - I just wanted to check in and see how things are going. Is there anything I can do to help? Happy to test out some kernel builds if needed. Thanks!

[Brian Murray (brian-murray)]

Ubuntu 23.10 (Mantic Minotaur) has reached end of life, so this bug will not be fixed for that specific release.

[roblabla (roblabla)]

Anything we can do to help move this forward?