USN-4727-1: Linux kernel vulnerability

Releases

• Ubuntu 20.10
• Ubuntu 20.04 LTS

Packages

• linux - Linux kernel
• linux-aws - Linux kernel for Amazon Web Services (AWS) systems
• linux-azure - Linux kernel for Microsoft Azure Cloud systems
• linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
• linux-hwe-5.8 - Linux hardware enablement (HWE) kernel
• linux-kvm - Linux kernel for cloud environments
• linux-oem-5.6 - Linux kernel for OEM systems
• linux-oracle - Linux kernel for Oracle Cloud systems
• linux-raspi - Linux kernel for Raspberry Pi (V8) systems

Details

Alexander Popov discovered that multiple race conditions existed in the
AF_VSOCK implementation in the Linux kernel. A local attacker could use
this to cause a denial of service (system crash) or execute arbitrary code.

Update instructions

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

Ubuntu 20.10

• linux-image-5.8.0-1015-raspi - 5.8.0-1015.18
• linux-image-5.8.0-1015-raspi-nolpae - 5.8.0-1015.18
• linux-image-5.8.0-1018-kvm - 5.8.0-1018.20
• linux-image-5.8.0-1020-oracle - 5.8.0-1020.21
• linux-image-5.8.0-1022-azure - 5.8.0-1022.24
• linux-image-5.8.0-1022-gcp - 5.8.0-1022.23
• linux-image-5.8.0-1023-aws - 5.8.0-1023.25
• linux-image-5.8.0-43-generic - 5.8.0-43.49
• linux-image-5.8.0-43-generic-64k - 5.8.0-43.49
• linux-image-5.8.0-43-generic-lpae - 5.8.0-43.49
• linux-image-5.8.0-43-lowlatency - 5.8.0-43.49
• linux-image-aws - 5.8.0.1023.25
• linux-image-azure - 5.8.0.1022.22
• linux-image-gcp - 5.8.0.1022.22
• linux-image-generic - 5.8.0.43.48
• linux-image-generic-64k - 5.8.0.43.48
• linux-image-generic-lpae - 5.8.0.43.48
• linux-image-gke - 5.8.0.1022.22
• linux-image-kvm - 5.8.0.1018.20
• linux-image-lowlatency - 5.8.0.43.48
• linux-image-oracle - 5.8.0.1020.19
• linux-image-raspi - 5.8.0.1015.18
• linux-image-raspi-nolpae - 5.8.0.1015.18
• linux-image-virtual - 5.8.0.43.48

Ubuntu 20.04

• linux-image-5.6.0-1047-oem - 5.6.0-1047.51
• linux-image-5.8.0-43-generic - 5.8.0-43.49~20.04.1
• linux-image-5.8.0-43-generic-lpae - 5.8.0-43.49~20.04.1
• linux-image-5.8.0-43-lowlatency - 5.8.0-43.49~20.04.1
• linux-image-generic-64k-hwe-20.04 - 5.8.0.43.49~20.04.29
• linux-image-generic-hwe-20.04 - 5.8.0.43.49~20.04.29
• linux-image-generic-lpae-hwe-20.04 - 5.8.0.43.49~20.04.29
• linux-image-lowlatency-hwe-20.04 - 5.8.0.43.49~20.04.29
• linux-image-oem-20.04 - 5.6.0.1047.43
• linux-image-virtual-hwe-20.04 - 5.8.0.43.49~20.04.29

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

• CVE-2021-26708