linux: MokSBState is ignored

[Tim Gardner]

Ubuntu-4.4.0-20.36 was released with signed module enforcement enabled, but contained no way of disabling secure boot for DKMS. Without these kernel patches it is possible to get your machine in an unbootable state, especially if you don't have a fallback kernel.

This patch set implements the ability to disable secure boot on demand from user space (with some password shennaigans). If one boots in secure boot mode and then installs a third party module (such as DKMS), then a dialog is displayed giving the user an option to disable secure boot, thereby also disabling module signature verification. Patch 1/2 is a scaffold patch of which only the GUID macros are actually used. The rest of the code is fenced by CONFIG_MODULE_SIG_UEFI which will not be enabled until a later series. Patch 2/2 is where MOKSBState is read and implemented. Patch 3/3 simply prints a bit more informative state information.

Information regarding secure boot and signed module enforcement will appear in the kernel log thusly:

'Secure boot enabled' - normal secure boot operation with signed module enforcement.
'Secure boot MOKSBState disabled' - UEFI Secure boot state has been over-ridden by MOKSBState. No signed module enforcement.

In the absense of a 'Secure boot' string assume that secure boot is disabled or does not exist.

[Tim Gardner (timg-tpi)]

Tested using a Qemu instance with ovmf installed. Looks to be doing what is expected.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-21.37

---------------
linux (4.4.0-21.37) xenial; urgency=low

  [ Tim Gardner ]

  * Release Tracking Bug
    - LP: #1571791

  * linux: MokSBState is ignored (LP: #1571691)
    - SAUCE: (noup) MODSIGN: Import certificates from UEFI Secure Boot
    - SAUCE: (noup) efi: Disable secure boot if shim is in insecure mode
    - SAUCE: (noup) Display MOKSBState when disabled

linux (4.4.0-20.36) xenial; urgency=low

  [ Tim Gardner ]

  * Release Tracking Bug
    - LP: #1571069

  * sysfs mount failure during stateful lxd snapshots (LP: #1570906)
    - SAUCE: kernfs: Do not match superblock in another user namespace when
      mounting

  * Kernel Panic in Ubuntu 16.04 netboot installer (LP: #1570441)
    - x86/topology: Fix logical package mapping
    - x86/topology: Fix Intel HT disable
    - x86/topology: Use total_cpus not nr_cpu_ids for logical packages
    - xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op
    - x86/topology: Fix AMD core count

  * [regression]: Failed to call clock_adjtime(): Invalid argument
    (LP: #1566465)
    - ntp: Fix ADJ_SETOFFSET being used w/ ADJ_NANO

linux (4.4.0-19.35) xenial; urgency=low

  [ Tim Gardner ]

  * Release Tracking Bug
    - LP: #1570348

  * CVE-2016-2847 (LP: #1554260)
    - pipe: limit the per-user amount of pages allocated in pipes

  * xenial kernel crash on HP BL460c G7 (qla24xx problem?) (LP: #1554003)
    - SAUCE: (noup) qla2xxx: Add irq affinity notification V2

  * arm64: guest hangs when ntpd is running (LP: #1549494)
    - SAUCE: (noup) KVM: arm/arm64: Handle forward time correction gracefully

  * linux: Enforce signed module loading when UEFI secure boot (LP: #1566221)
    - [Config] CONFIG_EFI_SECURE_BOOT_SIG_ENFORCE=y

  * s390/cpumf: Fix lpp detection (LP: #1555344)
    - s390/facilities: use stfl mnemonic instead of insn magic
    - s390/facilities: always use lowcore's stfle field for storing facility bits
    - s390/cpumf: Fix lpp detection

  * s390x kernel image needs weightwatchers (LP: #1536245)
    - [Config] s390x: Use compressed kernel bzImage

  * Surelock GA2 SP1: surelock02p05: Not seeing sgX devices for LUNs after
    upgrading to Ubuntu 16.04 (LP: #1567581)
    - Revert "UBUNTU: SAUCE: (noup) powerpc/pci: Assign fixed PHB number based on
      device-tree properties"

  * Backport upstream bugfixes to ubuntu-16.04 (LP: #1555765)
    - cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
    - Revert "cpufreq: postfix policy directory with the first CPU in related_cpus"
    - cpufreq: powernv: Add sysfs attributes to show throttle stats

  * systemd-modules-load.service: Failing due to missing module 'ib_iser' (LP: #1566468)
    - [Config] Add ib_iser to generic inclusion list

  * thunderx nic performance improvements (LP: #1567093)
    - net: thunderx: Set recevie buffer page usage count in bulk
    - net: thunderx: Adjust nicvf structure to reduce cache misses

  * fixes for thunderx nic in multiqueue mode (LP: #1567091)
    - net: thunderx: Fix for multiqset not configured upon interface toggle
    - net: thunderx: Fix for HW TSO not enabled for secondary qsets
    - net: thund...

[Pavel Rojtberg (rojtberg)]

I have issues with this on trusty.
The log says "Secure boot enabled" and consequently the nvidia DKMS module can not be loaded.

At which point should I have been asked to select the secure boot behavior?

[Tim Gardner (timg-tpi)]

Try 'sudo apt-get install mokutil; sudo mokutil --disable-validation'

[Pavel Rojtberg (rojtberg)]

1. asks for a password
2. Setting SB State Failed
3. nothing says I should reboot
4. upon reboot configuration screen pops up and asks random characters from the password entered before
5. allows me to disable verification

in case the above is the correct user story, I have the following remark:

this seems to disable all verification after shim. Before the change the kernel was still verified and only the the modules were not.
Therefore I would say things were more secure before.

Is it possible to just disable signed module enforcement again?

[Pavel Rojtberg (rojtberg)]

re-read the initial description.
So if I get "[ 0.000000] Secure boot MOKSBState disabled", this is exactly what I want?

[Tim Gardner (timg-tpi)]

Yes, that message indicates that your kernel is _not_ in secure boot mode, i.e., it _will_ load any (appropriately compiled) module.

[Aleksandr Dubinsky (adubinsky)]

`mokutil --disable-validation` doesn't work for me. It gave the same "Failed to request new MokSB state" message, but upon reboot I did not get any prompt to re-enter the password. Had to disable secureboot in the bios.

Why was this even enabled when Canonical-provided drivers like nvidia-361 don't have signatures? Ridiculous.

[Ｖ字龍(Vdragon) (vdragon)]

@adubinsky
Make sure you have efivarfs mounted read-write and the mokutil command is run with root permission.

[Kamal Mostafa (kamalmostafa)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-trusty' to 'verification-done-trusty'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Kamal Mostafa (kamalmostafa)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-vivid' to 'verification-done-vivid'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Kamal Mostafa (kamalmostafa)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-wily' to 'verification-done-wily'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.2.0-42.49

---------------
linux (4.2.0-42.49) wily; urgency=low

  [ Ben Romer ]

  * Release Tracking Bug
    - LP: #1597053

  [ Josh Boyer ]

  * SAUCE: UEFI: acpi: Ignore acpi_rsdp kernel parameter when module
    loading is restricted
    - LP: #1566221
  * SAUCE: UEFI: efi: Make EFI_SECURE_BOOT_SIG_ENFORCE depend on EFI
    - LP: #1566221
  * SAUCE: UEFI MODSIGN: Import certificates from UEFI Secure Boot
    - LP: #1571691
  * SAUCE: UEFI: efi: Disable secure boot if shim is in insecure mode
    - LP: #1571691

  [ Matthew Garrett ]

  * SAUCE: UEFI: Add secure_modules() call
    - LP: #1566221
  * SAUCE: UEFI: PCI: Lock down BAR access when module security is enabled
    - LP: #1566221
  * SAUCE: UEFI: x86: Lock down IO port access when module security is
    enabled
    - LP: #1566221
  * SAUCE: UEFI: ACPI: Limit access to custom_method
    - LP: #1566221
  * SAUCE: UEFI: asus-wmi: Restrict debugfs interface when module loading
    is restricted
    - LP: #1566221
  * SAUCE: UEFI: Restrict /dev/mem and /dev/kmem when module loading is
    restricted
    - LP: #1566221
  * SAUCE: UEFI: kexec: Disable at runtime if the kernel enforces module
    loading restrictions
    - LP: #1566221
  * SAUCE: UEFI: x86: Restrict MSR access when module loading is restricted
    - LP: #1566221
  * SAUCE: UEFI: Add option to automatically enforce module signatures when
    in Secure Boot mode
    - LP: #1566221

  [ Stefan Bader ]

  * [Config] Add pm80xx scsi driver to d-i
    - LP: #1595628

  [ Tim Gardner ]

  * [Config] CONFIG_EFI_SECURE_BOOT_SIG_ENFORCE=y
  * SAUCE: UEFI: Display MOKSBState when disabled
    - LP: #1571691
  * SAUCE: UEFI: Add secure boot and MOK SB State disabled sysctl
    - LP: #1593075

  [ Upstream Kernel Changes ]

  * Revert "scsi: fix soft lockup in scsi_remove_target() on module
    removal"
    - LP: #1592552
  * ath10k: fix firmware assert in monitor mode
    - LP: #1592552
  * drm/i915: Fix race condition in intel_dp_destroy_mst_connector()
    - LP: #1592552
  * ath10k: fix debugfs pktlog_filter write
    - LP: #1592552
  * drm/i915: Call intel_dp_mst_resume() before resuming displays
    - LP: #1592552
  * ARM: mvebu: fix GPIO config on the Linksys boards
    - LP: #1592552
  * ath5k: Change led pin configuration for compaq c700 laptop
    - LP: #1592552, #972604
  * xfs: disallow rw remount on fs with unknown ro-compat features
    - LP: #1592552
  * xfs: Don't wrap growfs AGFL indexes
    - LP: #1592552
  * rtlwifi: rtl8723be: Add antenna select module parameter
    - LP: #1592552
  * rtlwifi: btcoexist: Implement antenna selection
    - LP: #1592552
  * drm/gma500: Fix possible out of bounds read
    - LP: #1592552
  * Bluetooth: vhci: fix open_timeout vs. hdev race
    - LP: #1592552
  * Bluetooth: vhci: purge unhandled skbs
    - LP: #1592552
  * cpuidle: Indicate when a device has been unregistered
    - LP: #1592552
  * mfd: intel_quark_i2c_gpio: Use clkdev_create()
    - LP: #1592552
  * mfd: intel_quark_i2c_gpio: Remove clock tree on error path
    - LP: #1592552
  * [media] media: v4l2-compat-ioctl32: fix missing reserved field copy in
    put_v4l2_create32
    -...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.19.0-65.73

---------------
linux (3.19.0-65.73) vivid; urgency=low

  [ Ben Romer ]

  * Release Tracking Bug
    - LP: #1596631

  [ Josh Boyer ]

  * SAUCE: UEFI: acpi: Ignore acpi_rsdp kernel parameter when module
    loading is restricted
    - LP: #1566221
  * SAUCE: UEFI: efi: Make EFI_SECURE_BOOT_SIG_ENFORCE depend on EFI
    - LP: #1566221
  * SAUCE: UEFI MODSIGN: Import certificates from UEFI Secure Boot
    - LP: #1571691
  * SAUCE: UEFI: efi: Disable secure boot if shim is in insecure mode
    - LP: #1571691

  [ Matthew Garrett ]

  * SAUCE: UEFI: Add secure_modules() call
    - LP: #1566221
  * SAUCE: UEFI: PCI: Lock down BAR access when module security is enabled
    - LP: #1566221
  * SAUCE: UEFI: x86: Lock down IO port access when module security is
    enabled
    - LP: #1566221
  * SAUCE: UEFI: ACPI: Limit access to custom_method
    - LP: #1566221
  * SAUCE: UEFI: asus-wmi: Restrict debugfs interface when module loading
    is restricted
    - LP: #1566221
  * SAUCE: UEFI: Restrict /dev/mem and /dev/kmem when module loading is
    restricted
    - LP: #1566221
  * SAUCE: UEFI: kexec: Disable at runtime if the kernel enforces module
    loading restrictions
    - LP: #1566221
  * SAUCE: UEFI: x86: Restrict MSR access when module loading is restricted
    - LP: #1566221
  * SAUCE: UEFI: Add option to automatically enforce module signatures when
    in Secure Boot mode
    - LP: #1566221

  [ Stefan Bader ]

  * [Config] Add pm80xx scsi driver to d-i
    - LP: #1595628

  [ Tim Gardner ]

  * [Config] CONFIG_EFI_SECURE_BOOT_SIG_ENFORCE=y
  * SAUCE: UEFI: Display MOKSBState when disabled
    - LP: #1571691
  * SAUCE: UEFI: Add secure boot and MOK SB State disabled sysctl
    - LP: #1593075

  [ Upstream Kernel Changes ]

  * HID: core: prevent out-of-bound readings
    - LP: #1579190
  * mm: migrate dirty page without clear_page_dirty_for_io etc
    - LP: #1581865
    - CVE-2016-3070

 -- Benjamin M Romer <email address hidden> Mon, 27 Jun 2016 12:37:48 -0400

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.13.0-92.139

---------------
linux (3.13.0-92.139) trusty; urgency=low

  [ Kamal Mostafa ]

  * Release Tracking Bug
    - LP: #1597060

  [ Josh Boyer ]

  * SAUCE: UEFI: acpi: Ignore acpi_rsdp kernel parameter when module
    loading is restricted
    - LP: #1566221
  * SAUCE: UEFI: efi: Make EFI_SECURE_BOOT_SIG_ENFORCE depend on EFI
    - LP: #1566221
  * SAUCE: UEFI MODSIGN: Import certificates from UEFI Secure Boot
    - LP: #1566221, #1571691
  * SAUCE: UEFI: efi: Disable secure boot if shim is in insecure mode
    - LP: #1566221, #1571691

  [ Matthew Garrett ]

  * SAUCE: UEFI: Add secure_modules() call
    - LP: #1566221
  * SAUCE: UEFI: PCI: Lock down BAR access when module security is enabled
    - LP: #1566221
  * SAUCE: UEFI: x86: Lock down IO port access when module security is
    enabled
    - LP: #1566221
  * SAUCE: UEFI: ACPI: Limit access to custom_method
    - LP: #1566221
  * SAUCE: UEFI: asus-wmi: Restrict debugfs interface when module loading
    is restricted
    - LP: #1566221
  * SAUCE: UEFI: Restrict /dev/mem and /dev/kmem when module loading is
    restricted
    - LP: #1566221
  * SAUCE: UEFI: kexec: Disable at runtime if the kernel enforces module
    loading restrictions
    - LP: #1566221
  * SAUCE: UEFI: x86: Restrict MSR access when module loading is restricted
    - LP: #1566221
  * SAUCE: UEFI: Add option to automatically enforce module signatures when
    in Secure Boot mode
    - LP: #1566221

  [ Stefan Bader ]

  * [Config] Add pm80xx scsi driver to d-i
    - LP: #1595628

  [ Tim Gardner ]

  * [Config] CONFIG_EFI_SECURE_BOOT_SIG_ENFORCE=y
  * SAUCE: UEFI: Display MOKSBState when disabled
    - LP: #1566221, #1571691
  * SAUCE: UEFI: Add secure boot and MOK SB State disabled sysctl
    - LP: #1593075
  * SAUCE: UEFI: Set EFI_SECURE_BOOT bit in x86_efi_facility
    - LP: #1593075
  * [Config] CONFIG_EFI=n for arm64
    - LP: #1566221

  [ Upstream Kernel Changes ]

  * powerpc/tm: Abort syscalls in active transactions
    - LP: #1572624
  * HID: core: prevent out-of-bound readings
    - LP: #1579190
  * efi: Add separate 32-bit/64-bit definitions
    - LP: #1566221
  * x86/efi: Build our own EFI services pointer table
    - LP: #1566221
  * mm: migrate dirty page without clear_page_dirty_for_io etc
    - LP: #1581865
    - CVE-2016-3070
  * oom_kill: change oom_kill.c to use for_each_thread()
    - LP: #1592429
  * oom_kill: has_intersects_mems_allowed() needs rcu_read_lock()
    - LP: #1592429
  * oom_kill: add rcu_read_lock() into find_lock_task_mm()
    - LP: #1592429
  * virtio_balloon: return the amount of freed memory from leak_balloon()
    - LP: #1587089
  * virtio_balloon: free some memory from balloon on OOM
    - LP: #1587089
  * virtio_ballon: change stub of release_pages_by_pfn
    - LP: #1587089
  * virtio_balloon: do not change memory amount visible via /proc/meminfo
    - LP: #1587089

 -- Kamal Mostafa <email address hidden> Tue, 28 Jun 2016 12:40:49 -0700

[Seth Forshee (sforshee)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-trusty' to 'verification-done-trusty'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!