使用 apt upgrade 或 dist-upgrade 时如何检查破坏自动更新内核的内容？

Question

我当前的系统版本是 18.04 LTS，内核 4.15.0-45-generic。由于CVE-2019-11477，我想将内核更新到固定版本 linux-image-4.15.0-52-generic。
我试过了sudo apt dist-upgrade，什么也没发生。但是当我使用时apt search linux-image-4.15.0-52，这个内核存在于官方仓库中。然后我手动安装了它。

根据Karel的回答，我在新的VPS上测试过，都可以更新内核。所以我认为是系统中的文件损坏了。如何检查？

root@ubuntu:/home/username# uname -a
Linux ubuntu 4.15.0-45-generic #48-Ubuntu SMP Tue Jan 29 16:28:13 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
root@ubuntu:/home/username# apt update
Hit:1 http://archive.ubuntu.com/ubuntu bionic InRelease                                                               
Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]                                           
Hit:3 http://ppa.launchpad.net/ondrej/nginx-mainline/ubuntu bionic InRelease                                                   
Hit:4 https://deb.nodesource.com/node_10.x bionic InRelease                                                                    
Get:5 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]                                  
Get:6 http://archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]
Fetched 252 kB in 2s (110 kB/s)    
Reading package lists... Done
Building dependency tree       
Reading state information... Done
All packages are up to date.
root@ubuntu:/home/username# apt search linux-image-4.15.0-52
Sorting... Done
Full Text Search... Done
linux-image-4.15.0-52-generic/bionic-updates 4.15.0-52.56 amd64
  Signed kernel image generic

linux-image-4.15.0-52-lowlatency/bionic-updates 4.15.0-52.56 amd64
  Signed kernel image lowlatency
root@ubuntu:/home/username# apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
root@ubuntu:/home/username# apt dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

具有 18.04 LTS 的新 vps

Welcome to Ubuntu 18.04.2 LTS (GNU/Linux 4.15.0-50-generic x86_64)

root@vultr:~# apt upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following NEW packages will be installed:
  linux-headers-4.15.0-52 linux-headers-4.15.0-52-generic linux-image-4.15.0-52-generic
  linux-modules-4.15.0-52-generic linux-modules-extra-4.15.0-52-generic
The following packages will be upgraded:


root@vultr:~# apt dist-upgrade 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following NEW packages will be installed:
  linux-headers-4.15.0-52 linux-headers-4.15.0-52-generic linux-image-4.15.0-52-generic
  linux-modules-4.15.0-52-generic linux-modules-extra-4.15.0-52-generic
The following packages will be upgraded:

apt-cache policy linux-image-generic

root@ubuntu:/home/username# apt-cache policy linux-image-generic
linux-image-generic:
  Installed: (none)
  Candidate: 4.15.0.52.54
  Version table:
     4.15.0.52.54 500
        500 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
     4.15.0.51.53 500
        500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
     4.15.0.20.23 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages

Answer 1

您在系统上执行的操作删除了使这些升级“正常工作”的元包。

在linux-image-generic和linux-headers-generic包跟踪你的系统最新发布的内核版本- 4.15.0 -你需要安装它们得到提示升级。

sudo apt install linux-image-generic linux-headers-generic应该足以做到这一点。这也应该拉入您所追求的内核包的版本，尽管似乎您所在的任何镜像都没有 -52.56 而是 -52.54。