--- title: 'USN-4425-1: Linux kernel vulnerabilities | Ubuntu security notices' description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/notices/USN-4425-1 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-4425-1 --- # USN-4425-1: Linux kernel vulnerabilities Publication date 27 July 2020 Overview Several security issues were fixed in the Linux kernel. Releases [20.04 LTS](https://ubuntu.com/security/notices?release=focal) [18.04 LTS](https://ubuntu.com/security/notices?release=bionic) --- Open side navigation ## Packages * [linux](https://ubuntu.com/security/cves?package=linux) - Linux kernel * [linux-aws](https://ubuntu.com/security/cves?package=linux-aws) - Linux kernel for Amazon Web Services (AWS) systems * [linux-azure](https://ubuntu.com/security/cves?package=linux-azure) - Linux kernel for Microsoft Azure Cloud systems * [linux-azure-5.4](https://ubuntu.com/security/cves?package=linux-azure-5.4) - linux kernel for microsoft azure cloud systems * [linux-gcp](https://ubuntu.com/security/cves?package=linux-gcp) - Linux kernel for Google Cloud Platform (GCP) systems * [linux-hwe-5.4](https://ubuntu.com/security/cves?package=linux-hwe-5.4) - Linux hardware enablement (HWE) kernel * [linux-kvm](https://ubuntu.com/security/cves?package=linux-kvm) - Linux kernel for cloud environments * [linux-oracle](https://ubuntu.com/security/cves?package=linux-oracle) - Linux kernel for Oracle Cloud systems * [linux-raspi](https://ubuntu.com/security/cves?package=linux-raspi) - Linux kernel for Raspberry Pi (V8) systems * [linux-raspi-5.4](https://ubuntu.com/security/cves?package=linux-raspi-5.4) - Linux kernel for Raspberry Pi (V8) systems * [linux-riscv](https://ubuntu.com/security/cves?package=linux-riscv) - Linux kernel for RISC-V systems ## Details It was discovered that the network block device (nbd) implementation in the Linux kernel did not properly check for error conditions in some situations. An attacker could possibly use this to cause a denial of service (system crash). ([CVE-2019-16089](https://ubuntu.com/security/CVE-2019-16089)) It was discovered that the kernel->user space relay implementation in the Linux kernel did not properly check return values in some situations. A local attacker could possibly use this to cause a denial of service (system crash). ([CVE-2019-19462](https://ubuntu.com/security/CVE-2019-19462)) 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](https://ubuntu.com/security/CVE-2020-11935)) Jason A. Donenfeld discovered that the ACPI implementation in... --- Show more ## Update instructions After a standard system update you need to reboot your computer to make all the necessary changes. [Learn more about how to get the fixes.](https://ubuntu.com/security/cves/about#security) 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. The problem can be corrected by updating your system to the following package versions: | Ubuntu Release | Package Version | | --- | --- | | 20.04 LTS focal | [linux-image-5.4.0-1015-raspi](https://launchpad.net/ubuntu/+source/linux-raspi) –  [5.4.0-1015.15](https://launchpad.net/ubuntu/+source/linux-raspi/5.4.0-1015.15) | | | | [linux-image-5.4.0-1020-aws](https://launchpad.net/ubuntu/+source/linux-aws) –  [5.4.0-1020.20](https://launchpad.net/ubuntu/+source/linux-aws/5.4.0-1020.20) | | | | [linux-image-5.4.0-1021-gcp](https://launchpad.net/ubuntu/+source/linux-signed-gcp) –  [5.4.0-1021.21](https://launchpad.net/ubuntu/+source/linux-signed-gcp/5.4.0-1021.21) | | | | [linux-image-5.4.0-1021-oracle](https://launchpad.net/ubuntu/+source/linux-signed-oracle) –  [5.4.0-1021.21](https://launchpad.net/ubuntu/+source/linux-signed-oracle/5.4.0-1021.21) | | | | [linux-image-5.4.0-1022-azure](https://launchpad.net/ubuntu/+source/linux-signed-azure) –  [5.4.0-1022.22](https://launchpad.net/ubuntu/+source/linux-signed-azure/5.4.0-1022.22) | | | | [linux-image-5.4.0-30-generic](https://launchpad.net/ubuntu/+source/linux-riscv) –  [5.4.0-30.34](https://launchpad.net/ubuntu/+source/linux-riscv/5.4.0-30.34) | | | | [linux-image-5.4.0-42-generic](https://launchpad.net/ubuntu/+source/linux-signed) –  [5.4.0-42.46](https://launchpad.net/ubuntu/+source/linux-signed/5.4.0-42.46) | | | | [linux-image-5.4.0-42-generic-lpae](https://launchpad.net/ubuntu/+source/linux) –  [5.4.0-42.46](https://launchpad.net/ubuntu/+source/linux/5.4.0-42.46) | | | | [linux-image-5.4.0-42-lowlatency](https://launchpad.net/ubuntu/+source/linux-signed) –  [5.4.0-42.46](https://launchpad.net/ubuntu/+source/linux-signed/5.4.0-42.46) | | | | [linux-image-aws](https://launchpad.net/ubuntu/+source/linux-meta-aws) –  [5.4.0.1020.21](https://launchpad.net/ubuntu/+source/linux-meta-aws/5.4.0.1020.21) | | | | [linux-image-azure](https://launchpad.net/ubuntu/+source/linux-meta-azure) –  [5.4.0.1022.21](https://launchpad.net/ubuntu/+source/linux-meta-azure/5.4.0.1022.21) | | | | [linux-image-gcp](https://launchpad.net/ubuntu/+source/linux-meta-gcp) –  [5.4.0.1021.19](https://launchpad.net/ubuntu/+source/linux-meta-gcp/5.4.0.1021.19) | | | | [linux-image-generic](https://launchpad.net/ubuntu/+source/linux-meta) –  [5.4.0.42.45](https://launchpad.net/ubuntu/+source/linux-meta/5.4.0.42.45) | | | | [linux-image-generic-lpae](https://launchpad.net/ubuntu/+source/linux-meta) –  [5.4.0.42.45](https://launchpad.net/ubuntu/+source/linux-meta/5.4.0.42.45) | | | | [linux-image-gke](https://launchpad.net/ubuntu/+source/linux-meta-gcp) –  [5.4.0.1021.19](https://launchpad.net/ubuntu/+source/linux-meta-gcp/5.4.0.1021.19) | | | | [linux-image-kvm](https://launchpad.net/ubuntu/+source/linux-meta-kvm) –  [5.4.0.1020.19](https://launchpad.net/ubuntu/+source/linux-meta-kvm/5.4.0.1020.19) | | | | [linux-image-lowlatency](https://launchpad.net/ubuntu/+source/linux-meta) –  [5.4.0.42.45](https://launchpad.net/ubuntu/+source/linux-meta/5.4.0.42.45) | | | | [linux-image-oem](https://launchpad.net/ubuntu/+source/linux-meta) –  [5.4.0.42.45](https://launchpad.net/ubuntu/+source/linux-meta/5.4.0.42.45) | | | | [linux-image-oem-osp1](https://launchpad.net/ubuntu/+source/linux-meta) –  [5.4.0.42.45](https://launchpad.net/ubuntu/+source/linux-meta/5.4.0.42.45) | | | | [linux-image-oracle](https://launchpad.net/ubuntu/+source/linux-meta-oracle) –  [5.4.0.1021.19](https://launchpad.net/ubuntu/+source/linux-meta-oracle/5.4.0.1021.19) | | | | [linux-image-raspi](https://launchpad.net/ubuntu/+source/linux-meta-raspi) –  [5.4.0.1015.50](https://launchpad.net/ubuntu/+source/linux-meta-raspi/5.4.0.1015.50) | | | | [linux-image-raspi2](https://launchpad.net/ubuntu/+source/linux-meta-raspi) –  [5.4.0.1015.50](https://launchpad.net/ubuntu/+source/linux-meta-raspi/5.4.0.1015.50) | | | | [linux-image-virtual](https://launchpad.net/ubuntu/+source/linux-meta) –  [5.4.0.42.45](https://launchpad.net/ubuntu/+source/linux-meta/5.4.0.42.45) | | | | 18.04 LTS bionic | [linux-image-5.4.0-1015-raspi](https://launchpad.net/ubuntu/+source/linux-raspi-5.4) –  [5.4.0-1015.15~18.04.1](https://launchpad.net/ubuntu/+source/linux-raspi-5.4/5.4.0-1015.15~18.04.1) | | | | [linux-image-5.4.0-1022-azure](https://launchpad.net/ubuntu/+source/linux-signed-azure-5.4) –  [5.4.0-1022.22~18.04.1](https://launchpad.net/ubuntu/+source/linux-signed-azure-5.4/5.4.0-1022.22~18.04.1) | | | | [linux-image-5.4.0-42-generic](https://launchpad.net/ubuntu/+source/linux-signed-hwe-5.4) –  [5.4.0-42.46~18.04.1](https://launchpad.net/ubuntu/+source/linux-signed-hwe-5.4/5.4.0-42.46~18.04.1) | | | | [linux-image-5.4.0-42-generic-lpae](https://launchpad.net/ubuntu/+source/linux-hwe-5.4) –  [5.4.0-42.46~18.04.1](https://launchpad.net/ubuntu/+source/linux-hwe-5.4/5.4.0-42.46~18.04.1) | | | | [linux-image-5.4.0-42-lowlatency](https://launchpad.net/ubuntu/+source/linux-signed-hwe-5.4) –  [5.4.0-42.46~18.04.1](https://launchpad.net/ubuntu/+source/linux-signed-hwe-5.4/5.4.0-42.46~18.04.1) | | | | [linux-image-azure-edge](https://launchpad.net/ubuntu/+source/linux-meta-azure-5.4) –  [5.4.0.1022.6](https://launchpad.net/ubuntu/+source/linux-meta-azure-5.4/5.4.0.1022.6) | | | | [linux-image-generic-hwe-18.04](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4) –  [5.4.0.42.46~18.04.35](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4/5.4.0.42.46~18.04.35) | | | | [linux-image-generic-lpae-hwe-18.04](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4) –  [5.4.0.42.46~18.04.35](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4/5.4.0.42.46~18.04.35) | | | | [linux-image-gkeop-5.4](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4) –  [5.4.0.42.46~18.04.35](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4/5.4.0.42.46~18.04.35) | | | | [linux-image-lowlatency-hwe-18.04](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4) –  [5.4.0.42.46~18.04.35](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4/5.4.0.42.46~18.04.35) | | | | [linux-image-raspi-hwe-18.04](https://launchpad.net/ubuntu/+source/linux-meta-raspi-5.4) –  [5.4.0.1015.19](https://launchpad.net/ubuntu/+source/linux-meta-raspi-5.4/5.4.0.1015.19) | | | | [linux-image-snapdragon-hwe-18.04](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4) –  [5.4.0.42.46~18.04.35](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4/5.4.0.42.46~18.04.35) | | | | [linux-image-virtual-hwe-18.04](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4) –  [5.4.0.42.46~18.04.35](https://launchpad.net/ubuntu/+source/linux-meta-hwe-5.4/5.4.0.42.46~18.04.35) | | | --- ### Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. [Get Ubuntu Pro](https://ubuntu.com/pro) ## References * [CVE-2020-15780](https://ubuntu.com/security/CVE-2020-15780) * [CVE-2020-11935](https://ubuntu.com/security/CVE-2020-11935) * [CVE-2019-19462](https://ubuntu.com/security/CVE-2019-19462) * [CVE-2019-16089](https://ubuntu.com/security/CVE-2019-16089) ## Related notices * [USN-4440-1](https://ubuntu.com/security/notices/USN-4440-1) * [USN-4439-1](https://ubuntu.com/security/notices/USN-4439-1) * [USN-4427-1](https://ubuntu.com/security/notices/USN-4427-1) * [USN-4426-1](https://ubuntu.com/security/notices/USN-4426-1) * [USN-4414-1](https://ubuntu.com/security/notices/USN-4414-1) * [LSN-0072-1](https://ubuntu.com/security/notices/LSN-0072-1) * [LSN-0070-1](https://ubuntu.com/security/notices/LSN-0070-1) --- Have additional questions? [Talk to a member of the team ›](https://wiki.ubuntu.com/SecurityTeam/FAQ?_ga=2.242131138.1744859116.1742138161-1500419473.1726851136&_gl=1*161muja*_gcl_au*MzUyMTIzNjI1LjE3MzYyNDQ4NTE.#Contact)