Ubuntu 24.04.3: Noble Numbat point release slips out quietly

Bugs in the current LTS are getting squished

The latest point release of the current Ubuntu LTS is here, with a new kernel and a host of improvements for server and desktop alike.

The Ubuntu 24.04.3 release includes a substantial list of fixes. There are updates for the bootloader used on RISC-V hardware, better networking configuration in the early stages of the boot process, and updates to QEMU, lib-virt, and cloud-init.

It now has LibreOffice 24.8.7 and Firefox 141, and a new version of snapd, 2.68.5. There are multiple updates to GNOME, including to the Mutter window manager and compositor and the Nautilus file manager. Updates to Gtk4 improve the handling of Unicode emoji and integration with the Orca screen reader, and to the Pipewire audio server.

We're focusing on GNOME because that is the only official LTS desktop with the full lifespan. The various flavors with other desktops, such as Kubuntu, Lubuntu, Xubuntu and so on don't get the full five years of updates that the GNOME edition does. As an example, the Kubuntu wiki page specifies that it only gets three years of updates. If you prefer one of the rapidly-changing desktops such as KDE Plasma or LXQt, you should consider running interim versions instead.

Ubuntu 24.04 "Noble Numbat" appeared in late April last year, just a couple of weeks after a delayed beta version. This appeared about two weeks late because of the zx library backdoor in March 2024. Other delays have plagued the Noble release cycle. The upgrade from the previous interim release was delayed, too. Then, in August, the first point release was held back two weeks. Six months ago, there was a one-week delay in the release of version 24.04.2.

According to the company's own statement, about 95 per cent of Ubuntu users stick to the LTS releases. That means that the roughly semi-annual point releases to LTS versions serve two separate purposes: they're both update roll-ups, and they're also newer install media for the latest hardware.

The first of these means that each point release incorporates all the bug fixes and updates issued since the previous point release. So, if you installed an earlier point release and you've kept it updated since, then you don't need to do anything: you'll get the latest point release automatically.

The second purpose of the point-releases is different in two separate ways. Canonical makes new installation images available for each point release. The direct benefit of this is that, if you install a new machine or VM from these updated images, then it has all the updates up to that point pre-installed, meaning the first update will be a lot smaller and quicker.

The new version also refreshes the thousands of device drivers included with the OS. The design of the Linux kernel means that the bulk of the system's device drivers are part of the kernel itself; the main exception are graphics drivers, which come with the X.org X11 server. (This does not apply to Wayland, which uses the DRM drivers in the kernel.)

If you want to install the ageing LTS release on shiny new hardware that might be younger than the OS, and so contain hardware that's newer than the bundled drivers, Canonical bundles a new kernel and graphics subsystem. The company calls these LTS Hardware Enablement Stacks, or HWE for short.

Each interim version of Ubuntu has a new kernel version, as you'd expect from a new version of the distro. But the first point release of an LTS arrives in August – before the next interim release. Those come out each October. As such, the first point release of an Ubuntu LTS has the latest build of the same kernel version with which it originally shipped. The HWE stack gets bundled from the second LTS point release onwards, when the OS and its drivers are over a year old.

So, in the the case of Noble, 24.04.1 came with kernel 6.8. Then 24.04.2 came with kernel 6.11 from 24.10 "Oracular Oriole". Now, 24.04.3 comes with kernel 6.14 from 25.04 "Plucky Puffin", plus version 25.0.7 of the Mesa 3D stack, including the new Mesa Amber drivers for older GPUs.

If you installed from the original release of the LTS, then your hardware is presumably working and has been all along. That means that you don't need the new HWE stack. So, working on the principle of "if it ain't broke don't fix it," users of the original LTS version do not automatically receive the new kernel and graphics stack. If you want it, you must install it manually. Canonical's kernel release cycle page has instructions.

As it happens, the FOSS desk upgraded his official Register issue laptop to Noble before it was officially available, so we were originally running 24.04 – point zero, so to speak. (As point 9 of the upgrade guide says, it's as simple as doing update-manager -d.) So, this machine didn't automatically get the HWE stack when it received the rest of 24.04.3. For this article, we grabbed the latest one with the following command:

sudo apt-get install --install-recommends linux-generic-hwe-24.04

We are happy to report that we are now on kernel 6.14, and the system works exactly as it did before. ®