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:
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 map-4.2. 0-42-generic 4.4.0-31- generic MODULE_ SIG_UEFI= y map-4.4. 0-31-generic load_uefi_ certs7
# grep load_uefi /boot/System.
# grep MODULE_SIG_UEFI config-
CONFIG_
# grep load_uefi System.
ffffffff81d8431b t load_uefi_certs
ffffffff81e917d8 t __initcall_
ProblemType: Bug 4.2.0-42- generic 4.2.0-42.49~14.04.1 ature: Ubuntu 4.2.0-42. 49~14.04. 1-generic 4.2.8-ckt12
DistroRelease: Ubuntu 14.04
Package: linux-image-
ProcVersionSign
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)