I tried kernel 4.15.0-rc9 and had the same kind of hard lockup. The system wouldn't react to mouse or keypresses after some idle time. The log is attached (the kernel was upgraded on Jan 24-th). There are many errors about soft lockups in the log, although the backtraces are different from 4.13.
** Attachment added: "Kernel 4.15.0-rc9 log" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1744379/+attachment/5042206/+files/kern_4.15.0rc9.log.gz -- 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/1744379 Title: tcp_fastretrans_alert kernel warnings, possible system hardlock Status in linux package in Ubuntu: Incomplete Bug description: I have experienced a full system lockup, not even SysRq+REISUB could reboot the system. In the kernel logs I noticed multiple tcp_fastretrans_alert warnings and the upstream bug (https://bugzilla.kernel.org/show_bug.cgi?id=195835, https://bugzilla.kernel.org/show_bug.cgi?id=60779) seems to indicate this may be the reason. In the attached kernel log, the hang happened immediately before the last reboot. ProblemType: Bug DistroRelease: Ubuntu 17.10 Package: linux-image-4.13.0-25-generic 4.13.0-25.29 ProcVersionSignature: Ubuntu 4.13.0-25.29-generic 4.13.13 Uname: Linux 4.13.0-25-generic x86_64 NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia ApportVersion: 2.20.7-0ubuntu3.7 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC3: lastique 3183 F.... pulseaudio /dev/snd/controlC1: lastique 3183 F.... pulseaudio /dev/snd/controlC2: lastique 3183 F.... pulseaudio /dev/snd/controlC0: lastique 3183 F.... pulseaudio CurrentDesktop: KDE Date: Fri Jan 19 22:26:36 2018 InstallationDate: Installed on 2015-05-01 (993 days ago) InstallationMedia: Kubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422) MachineType: System manufacturer System Product Name ProcFB: ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.13.0-25-generic root=UUID=a03f1835-52f9-4409-9da7-fe45770637ae ro quiet splash nomdmonddf nomdmonisw RelatedPackageVersions: linux-restricted-modules-4.13.0-25-generic N/A linux-backports-modules-4.13.0-25-generic N/A linux-firmware 1.169.1 RfKill: 0: hci0: Bluetooth Soft blocked: no Hard blocked: no SourcePackage: linux UpgradeStatus: Upgraded to artful on 2017-11-03 (76 days ago) dmi.bios.date: 11/09/2012 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 3603 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: P8Z68-V PRO dmi.board.vendor: ASUSTeK Computer INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3603:bd11/09/2012:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP8Z68-VPRO:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.version: System Version dmi.sys.vendor: System manufacturer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1744379/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp