症状：

内核更新可能会由于内核与驱动不匹配，导致系统无限重启
1.
方式一（apt命令）：

#查看已安装的内核
sudo dpkg --get-selections | grep linux

#查看正在使用的内核
uname -r

#使用apt命令禁止内核更新
sudo apt-mark hold linux-image-4.4.0-21-generic
sudo apt-mark hold linux-image-extra-4.4.0-21-generic

dpkg --list | grep linux-image
 dpkg --list | grep linux-headers
  dpkg --list | grep linux-modules
  
  apt-mark hold linux-image-5.4.0-70-generic
  apt-mark hold linux-headers-5.4.0-70-generic
  apt-mark hold linux-modules-extra-5.4.0-70-generic

#重启内核更新
sudo apt-mark unhold linux-image-4.4.0-21-generic
sudo apt-mark unhold linux-image-extra-4.4.0-21-generic

方式二（修改配置文件）：

修改以下文件

sudo vim /etc/apt/apt.conf.d/10periodic
sudo vim /etc/apt/apt.conf.d/20auto-upgrades

#关闭自动更新
APT::Periodic::Update-Package-Lists "0";
APT::Periodic::Download-Upgradeable-Packages "0";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "0";

#开启自动更新
APT::Periodic::Update-Package-Lists "2";
APT::Periodic::Download-Upgradeable-Packages "1";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "1";