USN-4486-1: Linux kernel vulnerability

02 September 2020

The Linux kernel could be made to crash if it mounted a malicious XFS file system.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-kvm - Linux kernel for cloud environments
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty
  • linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
  • linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors

Details

Wen Xu discovered that the XFS filesystem implementation in the Linux
kernel did not properly validate meta-data information. An attacker could
use this to construct a malicious xfs image that, when mounted, could cause
a denial of service (system crash).

Update instructions

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

Ubuntu 16.04
Ubuntu 14.04

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-3752-1: linux-image-4.15.0-33-lowlatency, linux-image-snapdragon, linux-image-4.15.0-33-snapdragon, linux-image-aws, linux-aws, linux-image-generic, linux-image-4.15.0-33-generic-lpae, linux-image-4.15.0-1020-aws, linux-image-raspi2, linux-image-4.15.0-1021-raspi2, linux-image-4.15.0-33-generic, linux-image-generic-lpae, linux-image-kvm, linux, linux-image-4.15.0-1020-kvm, linux-image-lowlatency, linux-image-4.15.0-1018-gcp, linux-image-gcp, linux-raspi2, linux-kvm, linux-gcp, linux-image-gke
  • USN-3752-2: linux-image-4.15.0-33-lowlatency, linux-image-generic-hwe-16.04, linux-hwe, linux-image-4.15.0-33-generic, linux-image-lowlatency-hwe-16.04, linux-image-generic-lpae-hwe-16.04, linux-image-4.15.0-33-generic-lpae
  • USN-3752-3: linux-image-4.15.0-1018-gcp, linux-image-gcp, linux-image-azure, linux-azure, linux-image-oem, linux-image-4.15.0-1022-azure, linux-image-azure-edge, linux-oem, linux-gcp, linux-image-gke, linux-image-4.15.0-1017-oem
  • USN-3754-1: linux-image-generic, linux-image-3.13.0-157-powerpc-e500mc, linux-image-3.13.0-157-powerpc64-emb, linux-image-powerpc-e500mc, linux-image-3.13.0-157-generic-lpae, linux-image-3.13.0-157-powerpc64-smp, linux-image-3.13.0-157-powerpc-smp, linux-image-generic-lpae, linux-image-3.13.0-157-generic, linux-image-powerpc-e500, linux, linux-image-3.13.0-157-powerpc-e500, linux-image-powerpc64-emb, linux-image-3.13.0-157-lowlatency, linux-image-powerpc-smp, linux-image-lowlatency, linux-image-powerpc64-smp