USN-4426-1: Linux kernel vulnerabilities
=========================================================================
Ubuntu Security Notice USN-4426-1
July 21, 2020
linux, linux-aws, linux-aws-hwe, linux-gcp, linux-gcp-4.15,
linux-gke-4.15, linux-kvm, linux-oem, linux-oracle, linux-raspi2
vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description:
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-gcp-4.15: Linux kernel for Google Cloud Platform (GCP) systems
- linux-gke-4.15: Linux kernel for Google Container Engine (GKE) systems
- linux-kvm: Linux kernel for cloud environments
- linux-oem: Linux kernel for OEM systems
- linux-oracle: Linux kernel for Oracle Cloud systems
- linux-raspi2: Linux kernel for Raspberry Pi (V7) systems
- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
Details:
Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading SSDT code from an EFI variable. A
privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2019-20908)
Fan Yang discovered that the mremap implementation in the Linux kernel did
not properly handle DAX Huge Pages. A local attacker with access to DAX
storage could use this to gain administrative privileges. (CVE-2020-10757)
Mauricio Faria de Oliveira discovered that the aufs implementation in the
Linux kernel improperly managed inode reference counts in the
vfsub_dentry_open() method. A local attacker could use this vulnerability
to cause a denial of service. (CVE-2020-11935)
Jason A. Donenfeld discovered that the ACPI implementation in the Linux
kernel did not properly restrict loading ACPI tables via configfs. A
privileged attacker could use this to bypass Secure Boot lockdown
restrictions and execute arbitrary code in the kernel. (CVE-2020-15780)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 18.04 LTS:
linux-image-4.15.0-1050-oracle 4.15.0-1050.54
linux-image-4.15.0-1066-gke 4.15.0-1066.69
linux-image-4.15.0-1067-raspi2 4.15.0-1067.71
linux-image-4.15.0-1071-kvm 4.15.0-1071.72
linux-image-4.15.0-1079-aws 4.15.0-1079.83
linux-image-4.15.0-1080-gcp 4.15.0-1080.90
linux-image-4.15.0-1093-oem 4.15.0-1093.103
linux-image-4.15.0-112-generic 4.15.0-112.113
linux-image-4.15.0-112-generic-lpae 4.15.0-112.113
linux-image-4.15.0-112-lowlatency 4.15.0-112.113
linux-image-aws-lts-18.04 4.15.0.1079.81
linux-image-gcp-lts-18.04 4.15.0.1080.96
linux-image-generic 4.15.0.112.100
linux-image-generic-lpae 4.15.0.112.100
linux-image-gke 4.15.0.1066.68
linux-image-gke-4.15 4.15.0.1066.68
linux-image-kvm 4.15.0.1071.67
linux-image-lowlatency 4.15.0.112.100
linux-image-oem 4.15.0.1093.96
linux-image-oracle-lts-18.04 4.15.0.1050.59
linux-image-powerpc-e500mc 4.15.0.112.100
linux-image-powerpc-smp 4.15.0.112.100
linux-image-powerpc64-emb 4.15.0.112.100
linux-image-powerpc64-smp 4.15.0.112.100
linux-image-raspi2 4.15.0.1067.65
linux-image-virtual 4.15.0.112.100
Ubuntu 16.04 LTS:
linux-image-4.15.0-1050-oracle 4.15.0-1050.54~16.04.1
linux-image-4.15.0-1079-aws 4.15.0-1079.83~16.04.1
linux-image-4.15.0-1080-gcp 4.15.0-1080.90~16.04.1
linux-image-aws-hwe 4.15.0.1079.76
linux-image-gcp 4.15.0.1080.82
linux-image-gke 4.15.0.1080.82
linux-image-oracle 4.15.0.1050.41
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:
https://usn.ubuntu.com/4426-1
CVE-2019-20908, CVE-2020-10757, CVE-2020-11935, CVE-2020-15780
Package Information:
https://launchpad.net/ubuntu/+source/linux/4.15.0-112.113
https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1079.83
https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1080.90
https://launchpad.net/ubuntu/+source/linux-gke-4.15/4.15.0-1066.69
https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1071.72
https://launchpad.net/ubuntu/+source/linux-oem/4.15.0-1093.103
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1050.54
https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1067.71
https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1079.83~16.04.1
https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1080.90~16.04.1
https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1050.54~16.04.1
A Linux kernel security update has been released for Ubuntu Linux 18.04 LTS and 16.04 LTS.
