[Bug 2152152] Re: KHO: Failed to reserve lowmem scratch buffer on every boot (Ubuntu 26.04)

** Tags added: kernel-daily-bug -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2152152 Title: KHO: Failed to reserve lowmem scratch buffer on every boot (Ubuntu 26.04) Status in linux package in Ubuntu: New Bug description: 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 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2152152/+subscriptions