Canonical has announced a new kernel policy that aims to use the latest possible Linux kernel for new Ubuntu releases. However, this policy carries a risk: Ubuntu 25.10, named "Questing Quokka," may ship with a kernel in "release candidate" (RC) status. This means users might receive an “unstable” kernel, although this term is more technical than suggestive of poor performance.
The kernel freeze date for Ubuntu 25.10 is set for September 25, 2025, while the stable version of Linux 6.17 is expected soon after. As a result, Ubuntu will likely have to include the RC version of this kernel in the release ISO. Brett Grandbois, a Canonical Engineer, stated that they are operating under the assumption that Ubuntu 25.10 will be in an unstable status regarding its kernel until further notice.
Once the ISO is frozen, the kernel version won’t change, but Canonical will provide updates to help stabilize the RC kernel into its final form. In case the RC version is not user-friendly enough at launch, Canonical has a backup plan involving a "bridge kernel," such as Linux 6.16, which would support users until the desired stable kernel is ready.
Despite the potential instability, for many users, the difference may be minimal. The kernel update, while delayed on the ISO, won’t ultimately affect the functionality or the overall experience significantly. Ultimately, having the latest kernel is beneficial for both regular and LTS users relying on hardware enablement updates.
Canonical Kernel Policy Announcement
Ubuntu 25.10 Information