Ubuntu: 4185-3 Moderate: Linux Kernel Vulnerability and Regression

ubuntu

November 13, 2019

Several issues were fixed in the Linux kernel.

Summary

Several issues were fixed in the Linux kernel.

Software Description:

- linux: Linux kernel

- linux-oem: Linux kernel for OEM processors

- linux-hwe: Linux hardware enablement (HWE) kernel

Details:

USN-4185-1 fixed vulnerabilities in the Linux kernel. It was discovered

that the kernel fix for CVE-2019-0155 (i915 missing Blitter Command

Streamer check) was incomplete on 64-bit Intel x86 systems. Also, the

update introduced a regression that broke KVM guests where extended

page tables (EPT) are disabled or not supported. This update addresses

both issues.

We apologize for the inconvenience.

Original advisory details:

Stephan van Schaik, Alyssa Milburn, Sebastian Österlund, Pietro Frigo,

Kaveh Razavi, Herbert Bos, Cristiano Giuffrida, Giorgi Maisuradze, Moritz

Lipp, Michael Schwarz, Daniel Gruss, and Jo Van Bulck discovered that Intel

processors using Transactional Synchronization Extensions (TSX) could

expose memory contents previously stored in mi...

Read the Full Advisory

Topics Covered

security advisory update vulnerability kernel ubuntu Linux regression

Update Instructions

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

Ubuntu 18.04 LTS:
  linux-image-4.15.0-1064-oem     4.15.0-1064.73
  linux-image-4.15.0-70-generic   4.15.0-70.79
  linux-image-4.15.0-70-generic-lpae  4.15.0-70.79
  linux-image-4.15.0-70-lowlatency  4.15.0-70.79
  linux-image-generic             4.15.0.70.72
  linux-image-generic-lpae        4.15.0.70.72
  linux-image-lowlatency          4.15.0.70.72
  linux-image-oem                 4.15.0.1064.68
  linux-image-virtual             4.15.0.70.72

Ubuntu 16.04 LTS:
  linux-image-4.15.0-70-generic   4.15.0-70.79~16.04.1
  linux-image-4.15.0-70-generic-lpae  4.15.0-70.79~16.04.1
  linux-image-4.15.0-70-lowlatency  4.15.0-70.79~16.04.1
  linux-image-generic-hwe-16.04   4.15.0.70.90
  linux-image-generic-lpae-hwe-16.04  4.15.0.70.90
  linux-image-lowlatency-hwe-16.04  4.15.0.70.90
  linux-image-oem                 4.15.0.70.90
  linux-image-virtual-hwe-16.04   4.15.0.70.90

Please note that mitigating the TSX (CVE-2019-11135) and i915
(CVE-2019-0154) issues requires corresponding microcode and graphics
firmware updates respectively.

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.