Ubuntu 18.04 LTS USN-5591-3 Critical: Kernel Crash Denial Of Service

ubuntu

September 1, 2022

The system could be made to crash or run programs as an administrator.

Summary

The system could be made to crash or run programs as an administrator.

Software Description:

- linux: Linux kernel

- linux-azure-4.15: Linux kernel for Microsoft Azure Cloud systems

- linux-dell300x: Linux kernel for Dell 300x platforms

- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems

- linux-kvm: Linux kernel for cloud environments

- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors

Details:

It was discovered that the virtual terminal driver in the Linux kernel

did not properly handle VGA console font changes, leading to an

out-of-bounds write. A local attacker could use this to cause a denial

of service (system crash) or possibly execute arbitrary code.

Topics Covered

security advisory service denial ubuntu linux update kernel crash

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 18.04 LTS:
   linux-image-4.15.0-1052-dell300x  4.15.0-1052.57
   linux-image-4.15.0-1126-kvm     4.15.0-1126.131
   linux-image-4.15.0-1135-gcp     4.15.0-1135.151
   linux-image-4.15.0-1136-snapdragon  4.15.0-1136.146
   linux-image-4.15.0-1150-azure   4.15.0-1150.165
   linux-image-4.15.0-192-generic  4.15.0-192.203
   linux-image-4.15.0-192-generic-lpae  4.15.0-192.203
   linux-image-4.15.0-192-lowlatency  4.15.0-192.203
   linux-image-azure-lts-18.04     4.15.0.1150.120
   linux-image-dell300x            4.15.0.1052.52
   linux-image-gcp-lts-18.04       4.15.0.1135.151
   linux-image-generic             4.15.0.192.177
   linux-image-generic-lpae        4.15.0.192.177
   linux-image-kvm                 4.15.0.1126.119
   linux-image-lowlatency          4.15.0.192.177
   linux-image-snapdragon          4.15.0.1136.137
   linux-image-virtual             4.15.0.192.177

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.