USN-4683-1: Linux kernel (OEM) vulnerability

07 January 2021

The system could be made to crash or expose sensitive information under certain conditions.

Releases

Packages

Details

Minh Yuan discovered that the framebuffer console driver in the Linux
kernel did not properly handle fonts in some conditions. A local attacker
could use this to cause a denial of service (system crash) or possibly
expose sensitive information (kernel memory).

Update instructions

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

Ubuntu 20.04

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-4679-1: linux-image-oem, linux-gke-5.4, linux-image-5.4.0-1034-oracle, linux-image-aws, linux-image-virtual-hwe-18.04-edge, linux-image-5.4.0-1033-gcp, linux-image-raspi2, linux-image-generic-lpae, linux-oracle, linux-image-azure-edge, linux-image-lowlatency-hwe-18.04, linux-image-virtual-hwe-18.04, linux-kvm, linux-image-raspi-hwe-18.04, linux-image-virtual-hwe-20.04, linux-aws-5.4, linux-image-lowlatency-hwe-20.04, linux-image-oracle, linux-raspi-5.4, linux-image-gke-5.4, linux-image-snapdragon-hwe-18.04, linux-image-5.4.0-1034-aws, linux-image-lowlatency-hwe-18.04-edge, linux-image-oem-osp1, linux-image-generic, linux-image-lowlatency, linux-image-generic-hwe-18.04-edge, linux-image-virtual, linux-hwe-5.4, linux-image-aws-edge, linux-image-kvm, linux-image-5.4.0-59-lowlatency, linux-oracle-5.4, linux-image-generic-lpae-hwe-18.04-edge, linux-gcp-5.4, linux-image-generic-lpae-hwe-20.04, linux-raspi, linux-image-raspi2-hwe-18.04, linux-image-oracle-edge, linux-image-generic-lpae-hwe-18.04, linux-image-5.4.0-1031-kvm, linux-image-5.4.0-59-generic-lpae, linux-image-generic-hwe-20.04, linux, linux-image-gcp-edge, linux-image-generic-hwe-18.04, linux-image-raspi-hwe-18.04-edge, linux-image-raspi2-hwe-18.04-edge, linux-image-5.4.0-1035-azure, linux-image-raspi, linux-gcp, linux-aws, linux-image-5.4.0-59-generic, linux-image-azure, linux-image-5.4.0-1033-gke, linux-azure, linux-image-snapdragon-hwe-18.04-edge, linux-image-5.4.0-1026-raspi, linux-image-gcp, linux-azure-5.4
  • USN-4680-1: linux-image-oem, linux-hwe, linux-image-gke, linux-image-powerpc-e500mc, linux-image-lowlatency-hwe-16.04, linux-image-virtual-hwe-16.04, linux-image-raspi2, linux-image-azure-lts-18.04, linux-image-gcp-lts-18.04, linux-image-azure-edge, linux-image-generic-lpae, linux-image-aws-hwe, linux-image-lowlatency-hwe-16.04-edge, linux-image-generic-lpae-hwe-16.04, linux-image-powerpc64-emb, linux-kvm, linux-oracle, linux-image-4.15.0-1077-raspi2, linux-image-virtual-hwe-16.04-edge, linux-image-oracle, linux-azure-4.15, linux-image-4.15.0-1062-oracle, linux-image-4.15.0-1103-azure, linux-image-generic, linux-image-lowlatency, linux-image-virtual, linux-image-kvm, linux-image-4.15.0-1091-aws, linux-snapdragon, linux-gcp-4.15, linux-aws-hwe, linux-image-generic-lpae-hwe-16.04-edge, linux-image-4.15.0-1094-snapdragon, linux-image-powerpc64-smp, linux, linux-image-generic-hwe-16.04, linux-image-4.15.0-1077-gke, linux-image-4.15.0-1091-gcp, linux-image-powerpc-smp, linux-image-4.15.0-129-generic, linux-gcp, linux-image-gke-4.15, linux-image-snapdragon, linux-aws, linux-image-azure, linux-raspi2, linux-image-generic-hwe-16.04-edge, linux-gke-4.15, linux-azure, linux-image-4.15.0-1082-kvm, linux-image-aws-lts-18.04, linux-image-4.15.0-129-lowlatency, linux-image-gcp, linux-image-oracle-lts-18.04, linux-image-4.15.0-129-generic-lpae
  • USN-4681-1: linux-image-generic-lts-vivid, linux-image-generic-lts-wily, linux-image-powerpc-smp-lts-xenial, linux-image-aws, linux-image-4.4.0-198-powerpc64-smp, linux-image-generic-lpae-lts-wily, linux-image-powerpc-e500mc, linux-image-powerpc-e500mc-lts-wily, linux-image-powerpc64-smp-lts-vivid, linux-image-raspi2, linux-image-generic-lpae, linux-image-powerpc64-emb, linux-image-4.4.0-198-powerpc64-emb, linux-kvm, linux-image-powerpc64-emb-lts-xenial, linux-image-powerpc-smp-lts-vivid, linux-image-4.4.0-198-powerpc-e500mc, linux-image-4.4.0-1147-snapdragon, linux-image-powerpc64-emb-lts-utopic, linux-image-powerpc64-smp-lts-xenial, linux-image-4.4.0-198-generic-lpae, linux-image-virtual-lts-xenial, linux-image-4.4.0-1143-raspi2, linux-image-generic, linux-image-generic-lts-utopic, linux-image-4.4.0-198-generic, linux-image-lowlatency, linux-image-virtual, linux-image-lowlatency-lts-utopic, linux-image-virtual-lts-utopic, linux-image-kvm, linux-image-powerpc-e500mc-lts-xenial, linux-image-lowlatency-lts-xenial, linux-image-powerpc64-smp-lts-wily, linux-image-powerpc64-emb-lts-vivid, linux-image-4.4.0-1119-aws, linux-snapdragon, linux-image-powerpc64-smp, linux, linux-image-lowlatency-lts-wily, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-smp-lts-utopic, linux-image-powerpc-e500mc-lts-utopic, linux-image-generic-lpae-lts-vivid, linux-image-powerpc64-emb-lts-wily, linux-image-4.4.0-1085-kvm, linux-image-powerpc-smp, linux-image-lowlatency-lts-vivid, linux-image-generic-lpae-lts-xenial, linux-lts-xenial, linux-image-4.4.0-198-powerpc-smp, linux-image-powerpc-e500mc-lts-vivid, linux-image-snapdragon, linux-aws, linux-image-4.4.0-198-lowlatency, linux-image-generic-lpae-lts-utopic, linux-image-virtual-lts-wily, linux-raspi2, linux-image-virtual-lts-vivid, linux-image-generic-lts-xenial, linux-image-4.4.0-1083-aws, linux-image-powerpc-smp-lts-wily
  • USN-4751-1: linux-image-raspi-nolpae, linux-image-generic-hwe-20.04-edge, linux-image-gke, linux-image-aws, linux-image-generic-lpae-hwe-20.04-edge, linux-image-5.8.0-44-generic, linux-image-generic-lpae, linux-oracle, linux-kvm, linux-image-virtual-hwe-20.04, linux-image-lowlatency-hwe-20.04, linux-image-oracle, linux-image-generic-64k-hwe-20.04-edge, linux-image-virtual-hwe-20.04-edge, linux-image-generic, linux-image-lowlatency, linux-image-generic-64k, linux-image-virtual, linux-image-5.8.0-44-lowlatency, linux-image-kvm, linux-image-oem-20.04, linux-image-generic-lpae-hwe-20.04, linux-raspi, linux-image-5.8.0-1021-oracle, linux-image-generic-64k-hwe-20.04, linux-image-5.8.0-1016-raspi, linux-image-generic-hwe-20.04, linux, linux-image-5.8.0-1019-kvm, linux-image-5.8.0-1023-azure, linux-hwe-5.8, linux-image-raspi, linux-gcp, linux-image-5.8.0-1024-aws, linux-aws, linux-image-5.8.0-1016-raspi-nolpae, linux-image-azure, linux-image-5.8.0-44-generic-lpae, linux-azure, linux-image-5.8.0-44-generic-64k, linux-image-gcp, linux-image-lowlatency-hwe-20.04-edge, linux-image-5.8.0-1023-gcp