USN-4006-1: Linux kernel vulnerability

04 June 2019

A system hardening measure could be bypassed.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • 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

Federico Manuel Bento discovered that the Linux kernel did not properly
apply Address Space Layout Randomization (ASLR) in some situations for
setuid a.out binaries. A local attacker could use this to improve the
chances of exploiting an existing vulnerability in a setuid a.out binary.

As a hardening measure, this update disables a.out support.

Update instructions

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

Ubuntu 18.10

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.

References

Related notices

  • USN-4006-2: linux-image-4.18.0-21-generic, linux-image-4.18.0-21-generic-lpae, linux-image-4.18.0-21-snapdragon, linux-hwe, linux-image-lowlatency-hwe-18.04, linux-image-generic-lpae-hwe-18.04, linux-image-virtual-hwe-18.04, linux-image-generic-hwe-18.04, linux-image-4.18.0-21-lowlatency, linux-image-snapdragon-hwe-18.04
  • USN-4007-1: linux-image-4.15.0-1033-gcp, linux-image-oracle, linux-image-generic-lpae-hwe-16.04-edge, linux-image-4.15.0-1035-kvm, linux-aws, linux-image-oem, linux-image-lowlatency-hwe-16.04-edge, linux-image-4.15.0-1054-snapdragon, linux-image-aws, linux-image-virtual-hwe-16.04, linux-image-4.15.0-1039-oem, linux-image-4.15.0-1014-oracle, linux-image-generic, linux-image-generic-lpae-hwe-16.04, linux-image-4.15.0-1037-raspi2, linux-image-snapdragon, linux-image-generic-lpae, linux-kvm, linux-image-kvm, linux-oracle, linux-gcp, linux-image-4.15.0-51-generic, linux-image-generic-hwe-16.04, linux-image-lowlatency-hwe-16.04, linux-raspi2, linux-snapdragon, linux-image-4.15.0-51-generic-lpae, linux, linux-image-4.15.0-51-lowlatency, linux-image-generic-hwe-16.04-edge, linux-image-virtual, linux-image-lowlatency, linux-image-gcp, linux-image-virtual-hwe-16.04-edge, linux-image-4.15.0-1040-aws, linux-oem, linux-image-raspi2
  • USN-4007-2: linux-image-4.15.0-51-lowlatency, linux-image-oracle, linux-image-aws-hwe, linux-image-oem, linux-hwe, linux-image-virtual-hwe-16.04, linux-image-4.15.0-1040-aws, linux-image-lowlatency-hwe-16.04, linux-oracle, linux-image-4.15.0-1014-oracle, linux-image-generic-lpae-hwe-16.04, linux-image-generic-hwe-16.04, linux-aws-hwe, linux-image-4.15.0-51-generic-lpae, linux-image-4.15.0-51-generic
  • USN-4008-1: linux-image-4.4.0-1084-aws, linux-aws, linux-image-4.4.0-150-generic, linux-image-powerpc-smp-lts-xenial, linux-image-powerpc64-emb-lts-utopic, linux-image-aws, linux-image-generic-lts-vivid, linux-image-4.4.0-150-powerpc64-emb, linux-image-lowlatency-lts-wily, linux-image-lowlatency-lts-utopic, linux-image-generic, linux-image-generic-lts-xenial, linux-image-4.4.0-150-lowlatency, linux-image-snapdragon, linux-image-powerpc64-smp-lts-wily, linux-image-4.4.0-1110-raspi2, linux-image-generic-lpae, linux-image-virtual-lts-wily, linux-image-lowlatency-lts-vivid, linux-kvm, linux-image-kvm, linux-image-4.4.0-150-generic-lpae, linux-image-virtual-lts-vivid, linux-image-powerpc64-smp-lts-vivid, linux-image-generic-lpae-lts-xenial, linux-image-generic-lpae-lts-wily, linux-image-powerpc-e500mc-lts-wily, linux-image-generic-lpae-lts-vivid, linux-image-powerpc-smp-lts-wily, linux-image-powerpc-e500mc, linux-image-lowlatency-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-generic-lpae-lts-utopic, linux-image-powerpc-smp-lts-vivid, linux-image-4.4.0-1114-snapdragon, linux-image-powerpc64-emb-lts-wily, linux-image-virtual-lts-xenial, linux-image-powerpc64-smp-lts-utopic, linux-image-4.4.0-150-powerpc64-smp, linux-image-4.4.0-150-powerpc-e500mc, linux-image-4.4.0-150-powerpc-smp, linux-image-powerpc64-smp, linux-image-generic-lts-utopic, linux-raspi2, linux-image-4.4.0-1047-kvm, linux-image-powerpc-e500mc-lts-utopic, linux-image-powerpc-smp, linux-image-generic-lts-wily, linux-snapdragon, linux, linux-image-virtual, linux-image-lowlatency, linux-image-powerpc64-emb, linux-image-virtual-lts-utopic, linux-image-powerpc-e500mc-lts-vivid, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc64-emb-lts-xenial, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-emb-lts-vivid, linux-image-raspi2
  • USN-4008-3: linux-aws, linux-image-4.4.0-150-generic, linux-image-powerpc-smp-lts-xenial, linux-image-aws, linux-image-4.4.0-150-powerpc64-emb, linux-image-generic-lts-xenial, linux-image-4.4.0-150-lowlatency, linux-image-4.4.0-1045-aws, linux-image-4.4.0-150-generic-lpae, linux-image-generic-lpae-lts-xenial, linux-lts-xenial, linux-image-lowlatency-lts-xenial, linux-image-powerpc-e500mc-lts-xenial, linux-image-virtual-lts-xenial, linux-image-4.4.0-150-powerpc64-smp, linux-image-4.4.0-150-powerpc-e500mc, linux-image-4.4.0-150-powerpc-smp, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc64-emb-lts-xenial