I wasn't able to reproduce the problem on Trusty, even with sssd installed.
/proc/version_signature Ubuntu 4.4.0-119.143~14.04.1-generic 4.4.114 /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-4.4.0-119-generic root=UUID=e57a614e-ad1a-449e-954d-ce832d128920 ro quiet splash vt.handoff=7 dmesg -t | grep -i microcode (with CPUs other than 0 removed) microcode: CPU0 microcode updated early to revision 0x2d, date = 2018-02-07 microcode: CPU0 sig=0x206a7, pf=0x2, revision=0x2d microcode: Microcode Update Driver: v2.01 <tig...@aivazian.fsnet.co.uk>, Peter Oruba -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1759920 Title: intel-microcode 3.20180312.0 causes lockup at login screen(w/ linux- image-4.13.0-37-generic) Status in intel-microcode package in Ubuntu: Invalid Status in linux package in Ubuntu: Invalid Status in intel-microcode source package in Trusty: Invalid Status in linux source package in Trusty: Fix Committed Status in intel-microcode source package in Xenial: Invalid Status in linux source package in Xenial: Fix Committed Status in intel-microcode source package in Artful: Invalid Status in linux source package in Artful: Fix Committed Bug description: [Impact] * Some systems experience kernel lockups after updating to the latest intel-microcode package or when receiving updated microcode from a BIOS update. * In many cases, the lockups occur before users can reach the login screen which makes it very difficult to debug/workaround. [Test Case] * The most reliable test case currently known is to install the sssd package. Lockups may occur during package installation (disable IBPB by writing 0 to /proc/sys/kernel/ibpb_enabled to prevent this from happening). A lockup will most likely occur just after booting the system up as the lock screen is displayed. [Regression Potential] * The fix is in the task switching code of the kernel so complexity of the change is relatively high. [Original Report] I don't know if this is a problem with the kernel or the microcode, but we have a significant number of computers in our organization (on both 16.04 and 17.10) that fail if they have both updated. Booting with either linux-image-4.13.0-36-generic or intel-microcode 3.20180108.0+really20170707ubuntu17.10.1 allows all these computers to boot. ## Workaround ## 1. Boot the system with the dis_ucode_ldr kernel boot parameter to temporary avoid the problem: https://wiki.ubuntu.com/Kernel/KernelBootParameters 2. Install the previous version of package from https://launchpad.net/~ubuntu-security-proposed/+archive/ubuntu/ppa/+build/14261530/+files/intel-microcode_3.20180108.0+really20170707ubuntu16.04.1_amd64.deb 3. (Optional) Hold the package so that it won't be upgraded accidentally sudo apt-mark hold intel-microcode To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/intel-microcode/+bug/1759920/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : firstname.lastname@example.org Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp