Ubuntu 18.10: USN-3835-1 Moderate: Kernel Security Issues and Updates

ubuntu

December 3, 2018

Several security issues were fixed in the Linux kernel.

Summary

Several security issues were fixed in the Linux kernel.

Software Description:

- linux: Linux kernel

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

- linux-kvm: Linux kernel for cloud environments

- linux-raspi2: Linux kernel for Raspberry Pi 2

Details:

Jann Horn discovered that the procfs file system implementation in the

Linux kernel did not properly restrict the ability to inspect the kernel

stack of an arbitrary task. A local attacker could use this to expose

sensitive information. (CVE-2018-17972)

Jann Horn discovered that the mremap() system call in the Linux kernel did

not properly flush the TLB when completing, potentially leaving access to a

physical page after it has been released to the page allocator. A local

attacker could use this to cause a denial of service (system crash), expose

sensitive information, or possibly execute arbitrary code. (CVE-2018-18281)

It was discovered that the BPF verifier in the Linux kernel did not

correctly compute nume...

Read the Full Advisory

Topics Covered

security advisory moderate kernel update ubuntu system crash data exposure linux kernel

Update Instructions

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

Ubuntu 18.10:
  linux-image-4.18.0-1004-gcp     4.18.0-1004.5
  linux-image-4.18.0-1005-kvm     4.18.0-1005.5
  linux-image-4.18.0-1007-raspi2  4.18.0-1007.9
  linux-image-4.18.0-12-generic   4.18.0-12.13
  linux-image-4.18.0-12-generic-lpae  4.18.0-12.13
  linux-image-4.18.0-12-lowlatency  4.18.0-12.13
  linux-image-4.18.0-12-snapdragon  4.18.0-12.13
  linux-image-gcp                 4.18.0.1004.4
  linux-image-generic             4.18.0.12.13
  linux-image-generic-lpae        4.18.0.12.13
  linux-image-gke                 4.18.0.1004.4
  linux-image-kvm                 4.18.0.1005.5
  linux-image-lowlatency          4.18.0.12.13
  linux-image-raspi2              4.18.0.1007.4
  linux-image-snapdragon          4.18.0.12.13

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.