Recently, Canonical announced for Ubuntu 18.04 LTS and Ubuntu 16.04 LTS's new version of the kernel (based on Linux Kernel 4.15), this version fixes a regression error, official strongly recommends that users upgrade as soon as possible.
Earlier this month, Canonical released Ubuntu for all supported operating systems of the major Linux kernel security updates , fixes at least 28 security vulnerabilities. But in this update, a security patch introduced a regression error, resulting in Ubuntu 18.04 LTS and Ubuntu 16.04 LTS version of Linux 4.15 kernel panic when processing fragmented packets.
Canonical in security bulletin representation: "USN 4115-1 for Ubuntu 18.04 LTS and Ubuntu 16.04 LTS Linux Kernel fixes security vulnerabilities in 4.15 Unfortunately, as part of the update, and in some cases, in dealing with fragmented packets. when introduced into the regression error causes a kernel crash. we apologize for any inconvenience caused. "
Update
Canonical urges all use Linux Kernel Ubuntu 4.15 in 18.04 LTS (Bionic Beaver) and Ubuntu 16.04.6 LTS (Xenial Xerus) users to update their systems as soon as possible, and each kernel upgrade to linux-image 4.15.0-62 and linux-image 4.15.0-62.69 ~ 16.04.1, to replace the old version of linux-image 4.15.0-60.67.
此外，用于 Amazon Web Services（AWS），Google Container Engine（GKE），Google Cloud Platform（GCP），Microsoft Azure Cloud，Amazon Web Services（AWS-HWE）和 Oracle Cloud 的系统，以及云环境和 Raspberry Pi 2 设备也进行了针对 Linux 4.15 内核的修复，因此请相应地进行更新。
如需更新系统，请按照 Canonical 提供的说明进行操作，网址为 https://wiki.ubuntu.com/Security/Upgrades。
最后，确保在安装新版本内核后重新启动计算机以进行所有必要的更改。此外，还可能需要重新安装已安装的任何第三方内核模块。