========================================================================= Ubuntu Security Notice USN-4425-1 July 21, 2020 linux, linux-aws, linux-gcp, linux-hwe-5.4, linux-kvm, linux-oracle, linux-raspi-5.4, linux-riscv vulnerabilities ========================================================================= A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 20.04 LTS - Ubuntu 18.04 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: Linux kernel for Google Cloud Platform (GCP) systems - linux-kvm: Linux kernel for cloud environments - linux-oracle: Linux kernel for Oracle Cloud systems - linux-riscv: Linux kernel for RISC-V systems - linux-hwe-5.4: Linux hardware enablement (HWE) kernel - linux-raspi-5.4: Linux kernel for Raspberry Pi (V8) 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) 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) 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 20.04 LTS: linux-image-5.4.0-1020-aws 5.4.0-1020.20 linux-image-5.4.0-1021-gcp 5.4.0-1021.21 linux-image-5.4.0-1021-oracle 5.4.0-1021.21 linux-image-5.4.0-30-generic 5.4.0-30.34 linux-image-5.4.0-42-generic 5.4.0-42.46 linux-image-5.4.0-42-generic-lpae 5.4.0-42.46 linux-image-5.4.0-42-lowlatency 5.4.0-42.46 linux-image-aws 5.4.0.1020.21 linux-image-gcp 5.4.0.1021.19 linux-image-generic 5.4.0.30.37 linux-image-generic-lpae 5.4.0.42.45 linux-image-gke 5.4.0.1021.19 linux-image-kvm 5.4.0.1020.19 linux-image-lowlatency 5.4.0.42.45 linux-image-oem 5.4.0.42.45 linux-image-oem-osp1 5.4.0.42.45 linux-image-oracle 5.4.0.1021.19 linux-image-virtual 5.4.0.30.37 Ubuntu 18.04 LTS: linux-image-5.4.0-1015-raspi 5.4.0-1015.15~18.04.1 linux-image-5.4.0-42-generic 5.4.0-42.46~18.04.1 linux-image-5.4.0-42-generic-lpae 5.4.0-42.46~18.04.1 linux-image-5.4.0-42-lowlatency 5.4.0-42.46~18.04.1 linux-image-generic-hwe-18.04 5.4.0.42.46~18.04.35 linux-image-generic-lpae-hwe-18.04 5.4.0.42.46~18.04.35 linux-image-gkeop-5.4 5.4.0.42.46~18.04.35 linux-image-lowlatency-hwe-18.04 5.4.0.42.46~18.04.35 linux-image-raspi-hwe-18.04 5.4.0.1015.19 linux-image-snapdragon-hwe-18.04 5.4.0.42.46~18.04.35 linux-image-virtual-hwe-18.04 5.4.0.42.46~18.04.35 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/4425-1 CVE-2019-16089, CVE-2019-19462, CVE-2020-11935, CVE-2020-15780 Package Information: https://launchpad.net/ubuntu/+source/linux/5.4.0-42.46 https://launchpad.net/ubuntu/+source/linux-aws/5.4.0-1020.20 https://launchpad.net/ubuntu/+source/linux-gcp/5.4.0-1021.21 https://launchpad.net/ubuntu/+source/linux-kvm/5.4.0-1020.20 https://launchpad.net/ubuntu/+source/linux-oracle/5.4.0-1021.21 https://launchpad.net/ubuntu/+source/linux-riscv/5.4.0-30.34 https://launchpad.net/ubuntu/+source/linux-hwe-5.4/5.4.0-42.46~18.04.1 https://launchpad.net/ubuntu/+source/linux-raspi-5.4/5.4.0-1015.15~18.04.1