I also have had random system freezes ever since I upgraded from 18.04 to 18.10, Linux 4.18.0-10-generic, solved by always booting into 4.15.0-36-generic. When the freezes happen, the screen simply stops, and no input is accepted, not even the usual REISUB.
teresaejunior@laptop ~> inxi -Fz System: Host: laptop Kernel: 4.15.0-36-generic x86_64 bits: 64 Desktop: Xfce 4.13.2 Distro: Ubuntu 18.10 (Cosmic Cuttlefish) Machine: Type: Laptop System: LENOVO product: 80JE v: Lenovo G40-80 serial: <filter> Mobo: LENOVO model: Lancer 4A1 v: SDK0E50515 STD serial: <filter> UEFI: LENOVO v: B0CN79WW date: 05/07/2015 Battery: ID-1: BAT0 charge: 26.4 Wh condition: 26.4/28.5 Wh (93%) CPU: Topology: Dual Core model: Intel Core i5-5200U bits: 64 type: MT MCP L2 cache: 3072 KiB Speed: 1397 MHz min/max: 500/2700 MHz Core speeds (MHz): 1: 1146 2: 1000 3: 1079 4: 1039 Graphics: Device-1: Intel HD Graphics 5500 driver: i915 v: kernel Display: x11 server: X.Org 1.20.1 driver: modesetting unloaded: fbdev,vesa resolution: 1366x768~60Hz OpenGL: renderer: Mesa DRI Intel HD Graphics 5500 (Broadwell GT2) v: 4.5 Mesa 18.2.2 Audio: Device-1: Intel Broadwell-U Audio driver: snd_hda_intel Device-2: Intel Wildcat Point-LP High Definition Audio driver: snd_hda_intel Sound Server: ALSA v: k4.15.0-36-generic Network: Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet driver: r8169 IF: enp2s0 state: down mac: <filter> Device-2: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter driver: ath9k IF: wlp3s0 state: up mac: <filter> Device-3: Atheros AR3012 Bluetooth 4.0 type: USB driver: btusb IF-ID-1: docker0 state: down mac: <filter> Drives: Local Storage: total: 931.51 GiB used: 411.53 GiB (44.2%) ID-1: /dev/sda vendor: Seagate model: ST1000LM024 HN-M101MBB size: 931.51 GiB Partition: ID-1: / size: 915.71 GiB used: 411.52 GiB (44.9%) fs: ext4 dev: /dev/sda2 Sensors: System Temperatures: cpu: 41.0 C mobo: N/A Fan Speeds (RPM): N/A Info: Processes: 267 Uptime: 7h 12m Memory: 11.64 GiB used: 3.45 GiB (29.7%) Shell: fish inxi: 3.0.24 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1798961 Title: Random unrecoverable freezes on Ubuntu 18.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1798961/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs