========================================================================= Ubuntu Security Notice USN-4749-1 February 25, 2021 linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-gcp, linux-gcp-4.15, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities ========================================================================= A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 18.04 LTS - Ubuntu 16.04 LTS - Ubuntu 14.04 ESM 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-azure-4.15: Linux kernel for Microsoft Azure Cloud systems - linux-dell300x: Linux kernel for Dell 300x platforms - 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-oracle: Linux kernel for Oracle Cloud systems - linux-raspi2: Linux kernel for Raspberry Pi (V8) systems - linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors - linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems - linux-azure: Linux kernel for Microsoft Azure Cloud systems - linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems - linux-hwe: Linux hardware enablement (HWE) kernel Details: Bodong Zhao discovered a use-after-free in the Sun keyboard driver implementation in the Linux kernel. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2020-25669) It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815) Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in the Linux kernel did not correctly handle setting line discipline in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-27830, CVE-2020-28941) It was discovered that the memory management subsystem in the Linux kernel did not properly handle copy-on-write operations in some situations. A local attacker could possibly use this to gain unintended write access to read-only memory pages. (CVE-2020-29374) Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event processing backend in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29568) Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the Xen paravirt block backend in the Linux kernel, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29569) Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660) Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 18.04 LTS: linux-image-4.15.0-1012-dell300x 4.15.0-1012.16 linux-image-4.15.0-1065-oracle 4.15.0-1065.73 linux-image-4.15.0-1079-gke 4.15.0-1079.84 linux-image-4.15.0-1079-raspi2 4.15.0-1079.84 linux-image-4.15.0-1085-kvm 4.15.0-1085.87 linux-image-4.15.0-1093-gcp 4.15.0-1093.106 linux-image-4.15.0-1094-aws 4.15.0-1094.101 linux-image-4.15.0-1096-snapdragon 4.15.0-1096.105 linux-image-4.15.0-1108-azure 4.15.0-1108.120 linux-image-4.15.0-136-generic 4.15.0-136.140 linux-image-4.15.0-136-generic-lpae 4.15.0-136.140 linux-image-4.15.0-136-lowlatency 4.15.0-136.140 linux-image-aws-lts-18.04 4.15.0.1094.97 linux-image-azure-lts-18.04 4.15.0.1108.81 linux-image-dell300x 4.15.0.1012.14 linux-image-gcp-lts-18.04 4.15.0.1093.111 linux-image-generic 4.15.0.136.123 linux-image-generic-lpae 4.15.0.136.123 linux-image-gke 4.15.0.1079.83 linux-image-gke-4.15 4.15.0.1079.83 linux-image-kvm 4.15.0.1085.81 linux-image-lowlatency 4.15.0.136.123 linux-image-oracle-lts-18.04 4.15.0.1065.75 linux-image-powerpc-e500mc 4.15.0.136.123 linux-image-powerpc-smp 4.15.0.136.123 linux-image-powerpc64-emb 4.15.0.136.123 linux-image-powerpc64-smp 4.15.0.136.123 linux-image-raspi2 4.15.0.1079.76 linux-image-snapdragon 4.15.0.1096.99 linux-image-virtual 4.15.0.136.123 Ubuntu 16.04 LTS: linux-image-4.15.0-1065-oracle 4.15.0-1065.73~16.04.1 linux-image-4.15.0-1093-gcp 4.15.0-1093.106~16.04.1 linux-image-4.15.0-1094-aws 4.15.0-1094.101~16.04.1 linux-image-4.15.0-1108-azure 4.15.0-1108.120~16.04.1 linux-image-4.15.0-136-generic 4.15.0-136.140~16.04.1 linux-image-4.15.0-136-generic-lpae 4.15.0-136.140~16.04.1 linux-image-4.15.0-136-lowlatency 4.15.0-136.140~16.04.1 linux-image-aws-hwe 4.15.0.1094.87 linux-image-azure 4.15.0.1108.99 linux-image-gcp 4.15.0.1093.94 linux-image-generic-hwe-16.04 4.15.0.136.132 linux-image-generic-lpae-hwe-16.04 4.15.0.136.132 linux-image-gke 4.15.0.1093.94 linux-image-lowlatency-hwe-16.04 4.15.0.136.132 linux-image-oem 4.15.0.136.132 linux-image-oracle 4.15.0.1065.53 linux-image-virtual-hwe-16.04 4.15.0.136.132 Ubuntu 14.04 ESM: linux-image-4.15.0-1108-azure 4.15.0-1108.120~14.04.1 linux-image-azure 4.15.0.1108.81 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/4749-1 CVE-2020-25669, CVE-2020-27815, CVE-2020-27830, CVE-2020-28941, CVE-2020-29374, CVE-2020-29568, CVE-2020-29569, CVE-2020-29660, CVE-2020-29661 Package Information: https://launchpad.net/ubuntu/+source/linux/4.15.0-136.140 https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1094.101 https://launchpad.net/ubuntu/+source/linux-azure-4.15/4.15.0-1108.120 https://launchpad.net/ubuntu/+source/linux-dell300x/4.15.0-1012.16 https://launchpad.net/ubuntu/+source/linux-gcp-4.15/4.15.0-1093.106 https://launchpad.net/ubuntu/+source/linux-gke-4.15/4.15.0-1079.84 https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1085.87 https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1065.73 https://launchpad.net/ubuntu/+source/linux-raspi2/4.15.0-1079.84 https://launchpad.net/ubuntu/+source/linux-snapdragon/4.15.0-1096.105 https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1094.101~16.04.1 https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1108.120~16.04.1 https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1093.106~16.04.1 https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-136.140~16.04.1 https://launchpad.net/ubuntu/+source/linux-oracle/4.15.0-1065.73~16.04.1