USN-3823-1: Linux kernel vulnerabilities

15 November 2018

Several security issues were mitigated in the Linux kernel.

Releases

Packages

Details

It was discovered that memory present in the L1 data cache of an Intel CPU
core may be exposed to a malicious process that is executing on the CPU
core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local
attacker in a guest virtual machine could use this to expose sensitive
information (memory from other guests or the host OS). (CVE-2018-3646)

It was discovered that memory present in the L1 data cache of an Intel CPU
core may be exposed to a malicious process that is executing on the CPU
core. This vulnerability is also known as L1 Terminal Fault (L1TF). A local
attacker could use this to expose sensitive information (memory from the
kernel or other processes). (CVE-2018-3620)

Update instructions

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

Ubuntu 12.04

Please note that the recommended mitigation for CVE-2018-3646 involves
updating processor microcode in addition to updating the kernel;
however, the kernel includes a fallback for processors that have not
received microcode updates.

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.

Related notices

  • USN-3742-1: linux, linux-image-3.13.0-155-generic-lpae, linux-image-3.13.0-155-powerpc64-emb, linux-image-generic-lpae, linux-image-3.13.0-155-powerpc-e500mc, linux-image-lowlatency, linux-image-powerpc-e500, linux-image-3.13.0-155-lowlatency, linux-image-3.13.0-155-powerpc-e500, linux-image-3.13.0-155-powerpc-smp, linux-image-powerpc-smp, linux-image-powerpc-e500mc, linux-image-powerpc64-emb, linux-image-3.13.0-155-generic, linux-image-generic, linux-image-powerpc64-smp, linux-image-3.13.0-155-powerpc64-smp
  • USN-3742-2: linux-image-3.13.0-155-generic-lpae, linux-image-generic-lpae-lts-trusty, linux-image-generic-lts-trusty, linux-image-3.13.0-155-generic, linux-lts-trusty
  • USN-3740-1: linux, linux-image-4.15.0-32-generic, linux-image-aws, linux-image-generic-lpae, linux-image-gke, linux-image-raspi2, linux-image-4.15.0-1015-oem, linux-image-kvm, linux-aws, linux-image-4.15.0-1021-azure, linux-image-4.15.0-1019-aws, linux-image-4.15.0-32-snapdragon, linux-gcp, linux-image-gcp, linux-image-snapdragon, linux-image-oem, linux-kvm, linux-image-4.15.0-1019-kvm, linux-image-4.15.0-32-lowlatency, linux-image-lowlatency, linux-raspi2, linux-image-azure-edge, linux-image-generic, linux-image-azure, linux-azure, linux-image-4.15.0-1017-gcp, linux-image-4.15.0-1020-raspi2, linux-image-4.15.0-32-generic-lpae, linux-oem
  • USN-3741-2: linux-image-powerpc-e500mc-lts-xenial, linux-aws, linux-image-4.4.0-133-powerpc64-emb, linux-image-generic-lpae-lts-xenial, linux-image-4.4.0-133-lowlatency, linux-image-aws, linux-image-4.4.0-133-powerpc-smp, linux-image-4.4.0-133-generic, linux-image-4.4.0-1027-aws, linux-image-powerpc64-smp-lts-xenial, linux-image-generic-lts-xenial, linux-image-4.4.0-133-powerpc64-smp, linux-image-powerpc-smp-lts-xenial, linux-image-lowlatency-lts-xenial, linux-lts-xenial, linux-image-4.4.0-133-powerpc-e500mc, linux-image-4.4.0-133-generic-lpae, linux-image-powerpc64-emb-lts-xenial
  • USN-3741-1: linux, linux-image-4.4.0-133-powerpc64-emb, linux-image-generic-lpae, linux-image-aws, linux-snapdragon, linux-image-raspi2, linux-image-powerpc-smp, linux-image-4.4.0-1094-raspi2, linux-image-4.4.0-133-powerpc64-smp, linux-image-kvm, linux-aws, linux-image-4.4.0-133-generic, linux-image-4.4.0-1098-snapdragon, linux-image-powerpc64-emb, linux-image-4.4.0-133-powerpc-e500mc, linux-image-4.4.0-1065-aws, linux-image-snapdragon, linux-kvm, linux-image-lowlatency, linux-image-4.4.0-133-lowlatency, linux-raspi2, linux-image-4.4.0-133-powerpc-smp, linux-image-powerpc-e500mc, linux-image-generic, linux-image-4.4.0-133-generic-lpae, linux-image-4.4.0-1031-kvm, linux-image-powerpc64-smp
  • USN-3756-1: intel-microcode
  • USN-3740-2: linux-image-lowlatency-hwe-16.04, linux-image-4.15.0-32-generic, linux-hwe, linux-image-4.15.0-32-lowlatency, linux-image-4.15.0-1021-azure, linux-image-gke, linux-image-virtual-hwe-16.04, linux-image-4.15.0-32-generic-lpae, linux-image-generic-lpae-hwe-16.04, linux-image-generic-hwe-16.04, linux-image-azure, linux-azure, linux-gcp, linux-image-gcp, linux-image-4.15.0-1017-gcp