Public bug reported: 4.2.0-42 was built without CONFIG_MODULE_SIG_UEFI so the kernel ignores the SecureBoot certificates and the user certificates enrolled as MOKs for module signature validation, forcing the user to either disable validation in shim through mokutil or disabling SecureBoot altogether.
The current linux-lts-xenial build has CONFIG_MODULE_SIG_UEFI=y in its config file and the related symbols (load_uefi_certs, get_cert_list...) are present in System.map. On the other end, the current linux-lts-wily build lacks both: # grep MODULE_SIG_UEFI /boot/config-4.2.0-42-generic # grep load_uefi /boot/System.map-4.2.0-42-generic # grep MODULE_SIG_UEFI config-4.4.0-31-generic CONFIG_MODULE_SIG_UEFI=y # grep load_uefi System.map-4.4.0-31-generic ffffffff81d8431b t load_uefi_certs ffffffff81e917d8 t __initcall_load_uefi_certs7 ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-4.2.0-42-generic 4.2.0-42.49~14.04.1 ProcVersionSignature: Ubuntu 4.2.0-42.49~14.04.1-generic 4.2.8-ckt12 Uname: Linux 4.2.0-42-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.21 Architecture: amd64 CurrentDesktop: XFCE Date: Wed Jul 20 21:18:31 2016 InstallationDate: Installed on 2016-01-24 (178 days ago) InstallationMedia: Xubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805) SourcePackage: linux-lts-wily UpgradeStatus: No upgrade log present (probably fresh install) ** Affects: linux-lts-wily (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug third-party-packages trusty -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1604934 Title: Missing support for loading modsig certificates from UEFI To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-wily/+bug/1604934/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs