Cloud-init causes potentially huge boot delays with 4.15 kernels

[Juerg Haefliger]

Newer 4.15 kernels contain the following fix for CVE-2018-1108:
  43838a23a05fb ("random: fix crng_ready() test")

This causes cloud-init to stall for a potentially long time during boot (waiting for entropy I presume). Google reported boot delays of 75 minutes.

I've tracked this down to the following import in templater.py which causes the delay:
    from jinja2 import Template as JTemplate

Which is called when cc_update_etc_hosts is imported.

[Juerg Haefliger (juergh)]

mvo: fwiw jinja2 imports random and that reads 2500 chars from /dev/urandom on import

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1780062

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[voidvector (voidvector)]

Appears to also effect Ubuntu Desktop with crng_init enabled.

* EC2 instances - effected, same problem as described
* Home Desktop (Xubuntu) - effected, see description below
* Home Server (Lubuntu that has crng_init=0 for some reason) - uneffected

cloud-init might just be a red-herring, as my Home Desktop would hang for 30+ seconds on "docker.service". When I disable Docker, it would still hang for 30 seconds, but "systemd-analyze blame" won't provide any culprit.

[Magnus Helander (mhelander)]

Can confirm - the weirdest bug, moving my finger on mousepad enables normal boot times.
Thinkpad T420
4.15.0-24-generic #26-Ubuntu SMP Wed Jun 13 08:44:47 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[Brad Figg (brad-figg)]

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-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

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!

[Louis Bouchard (louis)]

Hello,
I have noticed the same issue on our recently released scaleway images with cloud-init enabled on Bionic running 4.15.0-24.

Testing with the 4.15.0-26-generic kernel in -proposed _DOES_ fix the delay issue on our image.

I'm taking the liberty of marking the bug tested.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-29.31

---------------
linux (4.15.0-29.31) bionic; urgency=medium

  * linux: 4.15.0-29.31 -proposed tracker (LP: #1782173)

  * [SRU Bionic][Cosmic] kernel panic in ipmi_ssif at msg_done_handler
    (LP: #1777716)
    - ipmi_ssif: Fix kernel panic at msg_done_handler

  * Update to ocxl driver for 18.04.1 (LP: #1775786)
    - misc: ocxl: use put_device() instead of device_unregister()
    - powerpc: Add TIDR CPU feature for POWER9
    - powerpc: Use TIDR CPU feature to control TIDR allocation
    - powerpc: use task_pid_nr() for TID allocation
    - ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's action
    - ocxl: Expose the thread_id needed for wait on POWER9
    - ocxl: Add an IOCTL so userspace knows what OCXL features are available
    - ocxl: Document new OCXL IOCTLs
    - ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()

  * Critical upstream bugfix missing in Ubuntu 18.04 - frequent Xorg crash after
    suspend (LP: #1776887)
    - ocxl: Document the OCXL_IOCTL_GET_METADATA IOCTL

  * Hard LOCKUP observed on stressing Ubuntu 18 04 (LP: #1777194)
    - powerpc: use NMI IPI for smp_send_stop
    - powerpc: Fix smp_send_stop NMI IPI handling

  * IPL: ppc64_cpu --frequency hang with INFO: rcu_sched detected stalls on
    CPUs/tasks on w34 and wsbmc016 with 920.1714.20170330n (LP: #1773964)
    - rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops

  * [Regression] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383:
    comm stress-ng: bg 4705: bad block bitmap checksum (LP: #1781709)
    - SAUCE: Revert "UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm
      stress-ng: Corrupt inode bitmap"
    - SAUCE: ext4: check for allocation block validity with block group locked

linux (4.15.0-28.30) bionic; urgency=medium

  * linux: 4.15.0-28.30 -proposed tracker (LP: #1781433)

  * Cannot set MTU higher than 1500 in Xen instance (LP: #1781413)
    - xen-netfront: Fix mismatched rtnl_unlock
    - xen-netfront: Update features after registering netdev

linux (4.15.0-27.29) bionic; urgency=medium

  * linux: 4.15.0-27.29 -proposed tracker (LP: #1781062)

  * [Regression] EXT4-fs error (device sda1): ext4_validate_inode_bitmap:99:
    comm stress-ng: Corrupt inode bitmap (LP: #1780137)
    - SAUCE: ext4: fix ext4_validate_inode_bitmap: comm stress-ng: Corrupt inode
      bitmap

linux (4.15.0-26.28) bionic; urgency=medium

  * linux: 4.15.0-26.28 -proposed tracker (LP: #1780112)

  * failure to boot with linux-image-4.15.0-24-generic (LP: #1779827) // Cloud-
    init causes potentially huge boot delays with 4.15 kernels (LP: #1780062)
    - random: Make getrandom() ready earlier

linux (4.15.0-25.27) bionic; urgency=medium

  * linux: 4.15.0-25.27 -proposed tracker (LP: #1779354)

  * hisi_sas_v3_hw: internal task abort: timeout and not done. (LP: #1777736)
    - scsi: hisi_sas: Update a couple of register settings for v3 hw

  * hisi_sas: Add missing PHY spinlock init (LP: #1777734)
    - scsi: hisi_sas: Add missing PHY spinlock init

  * hisi_sas: improve read performance by pre-allocating slot DMA buffers
    (LP: #1777727)
    - scsi: hisi_sas: use dma_zalloc_cohe...

[Magnus Helander (mhelander)]

Bug fix verified - normal boot times. Thnks!
Linux think420 4.15.0-29-generic #31-Ubuntu SMP
Tue Jul 17 15:39:52 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.15.0-29.31

---------------
linux (4.15.0-29.31) bionic; urgency=medium

  * linux: 4.15.0-29.31 -proposed tracker (LP: #1782173)

  * [SRU Bionic][Cosmic] kernel panic in ipmi_ssif at msg_done_handler
    (LP: #1777716)
    - ipmi_ssif: Fix kernel panic at msg_done_handler

  * Update to ocxl driver for 18.04.1 (LP: #1775786)
    - misc: ocxl: use put_device() instead of device_unregister()
    - powerpc: Add TIDR CPU feature for POWER9
    - powerpc: Use TIDR CPU feature to control TIDR allocation
    - powerpc: use task_pid_nr() for TID allocation
    - ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's action
    - ocxl: Expose the thread_id needed for wait on POWER9
    - ocxl: Add an IOCTL so userspace knows what OCXL features are available
    - ocxl: Document new OCXL IOCTLs
    - ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()

  * Critical upstream bugfix missing in Ubuntu 18.04 - frequent Xorg crash after
    suspend (LP: #1776887)
    - ocxl: Document the OCXL_IOCTL_GET_METADATA IOCTL

  * Hard LOCKUP observed on stressing Ubuntu 18 04 (LP: #1777194)
    - powerpc: use NMI IPI for smp_send_stop
    - powerpc: Fix smp_send_stop NMI IPI handling

  * IPL: ppc64_cpu --frequency hang with INFO: rcu_sched detected stalls on
    CPUs/tasks on w34 and wsbmc016 with 920.1714.20170330n (LP: #1773964)
    - rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops

  * [Regression] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383:
    comm stress-ng: bg 4705: bad block bitmap checksum (LP: #1781709)
    - SAUCE: Revert "UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm
      stress-ng: Corrupt inode bitmap"
    - SAUCE: ext4: check for allocation block validity with block group locked

linux (4.15.0-28.30) bionic; urgency=medium

  * linux: 4.15.0-28.30 -proposed tracker (LP: #1781433)

  * Cannot set MTU higher than 1500 in Xen instance (LP: #1781413)
    - xen-netfront: Fix mismatched rtnl_unlock
    - xen-netfront: Update features after registering netdev

linux (4.15.0-27.29) bionic; urgency=medium

  * linux: 4.15.0-27.29 -proposed tracker (LP: #1781062)

  * [Regression] EXT4-fs error (device sda1): ext4_validate_inode_bitmap:99:
    comm stress-ng: Corrupt inode bitmap (LP: #1780137)
    - SAUCE: ext4: fix ext4_validate_inode_bitmap: comm stress-ng: Corrupt inode
      bitmap

linux (4.15.0-26.28) bionic; urgency=medium

  * linux: 4.15.0-26.28 -proposed tracker (LP: #1780112)

  * failure to boot with linux-image-4.15.0-24-generic (LP: #1779827) // Cloud-
    init causes potentially huge boot delays with 4.15 kernels (LP: #1780062)
    - random: Make getrandom() ready earlier

linux (4.15.0-25.27) bionic; urgency=medium

  * linux: 4.15.0-25.27 -proposed tracker (LP: #1779354)

  * hisi_sas_v3_hw: internal task abort: timeout and not done. (LP: #1777736)
    - scsi: hisi_sas: Update a couple of register settings for v3 hw

  * hisi_sas: Add missing PHY spinlock init (LP: #1777734)
    - scsi: hisi_sas: Add missing PHY spinlock init

  * hisi_sas: improve read performance by pre-allocating slot DMA buffers
    (LP: #1777727)
    - scsi: hisi_sas: use dma_zalloc_cohe...

[Kimball Johnson (engagilist)]

If this is fixed in 18.04, why does it still occur in Ubuntu Server 20.04?
I'm already at 40+ minutes!

[Juerg Haefliger (juergh)]

This is a closed ticket for Bionic. Could you please open a new ticket for Focal?