Public bug reported:
On every boot/reboot, the kernel logs this error:
KHO: Failed to reserve lowmem scratch buffer
This appears to be related to the Kexec HandOver (KHO) feature for
kernel live updates.
System details:
- Ubuntu 26.04 LTS
- Kernel: 7.0.0-15-generic
- kexec-tools is installed but kexec is not configured or in use
- The error appears in journalctl logs but system appears to function normally
otherwise
Steps to reproduce:
1. Boot Ubuntu 26.04 (with kexec-tools installed but not configured)
2. Run: journalctl -b -p err
3. Observe the KHO error message
Expected result: No kernel errors on clean boot when kexec is not in use
Actual result: KHO lowmem scratch buffer reservation fails during kernel init
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-15-generic 7.0.0-15.15
ProcVersionSignature: Ubuntu 7.0.0-15.15-generic 7.0.0
Uname: Linux 7.0.0-15-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version k7.0.0-15-generic.
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.34.0-0ubuntu2
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path',
'/dev/snd/controlC0', '/dev/snd/hwC0D3', '/dev/snd/hwC0D0',
'/dev/snd/pcmC0D3p', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/seq',
'/dev/snd/timer'] failed with exit code 1:
CRDA: N/A
Card0.Amixer.info: Error: [Errno 2] No such file or directory: 'amixer'
Card0.Amixer.values: Error: [Errno 2] No such file or directory: 'amixer'
CasperMD5CheckResult: pass
Date: Sun May 10 13:36:50 2026
InstallationDate: Installed on 2026-04-26 (15 days ago)
InstallationMedia: Ubuntu-Server 26.04 "Resolute Raccoon" - Release amd64
(20260420.1)
MachineType: LENOVO 1066AJU
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-15-generic
root=/dev/mapper/ubuntu--vg-ubuntu--lv ro
rd.luks.key=/luks/usb_keyfile:UUID=1b6d77f7-1a51-4316-8969-186acf70a5a4
rd.luks.key.tout=30 rd.retry=30 rd.timeout=60
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/22/2011
dmi.bios.release: 1.66
dmi.bios.vendor: LENOVO
dmi.bios.version: 44CN42WW
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Emerald Lake
dmi.board.vendor: LENOVO
dmi.board.version: FAB1
dmi.chassis.asset.tag: Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: 0.1
dmi.ec.firmware.release: 1.41
dmi.modalias:
dmi:bvnLENOVO:bvr44CN42WW:bd09/22/2011:br1.66:efr1.41:svnLENOVO:pn1066AJU:pvrLenovoV570:rvnLENOVO:rnEmeraldLake:rvrFAB1:cvnLENOVO:ct10:cvr0.1:skuSystemSKUNumber:pfaHuronRiverSystem:
dmi.product.family: HuronRiver System
dmi.product.name: 1066AJU
dmi.product.sku: System SKUNumber
dmi.product.version: Lenovo V570
dmi.sys.vendor: LENOVO
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2152152
Title:
KHO: Failed to reserve lowmem scratch buffer on every boot (Ubuntu
26.04)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2152152/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
