========================================================================= Ubuntu Security Notice USN-4576-1 October 14, 2020 linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 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-azure: Linux kernel for Microsoft Azure Cloud 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-raspi: Linux kernel for Raspberry Pi (V8) systems - linux-aws-5.4: Linux kernel for Amazon Web Services (AWS) systems - linux-azure-5.4: Linux kernel for Microsoft Azure cloud systems - linux-gcp-5.4: Linux kernel for Google Cloud Platform (GCP) systems - linux-hwe-5.4: Linux hardware enablement (HWE) kernel - linux-oracle-5.4: Linux kernel for Oracle Cloud systems - linux-raspi-5.4: Linux kernel for Raspberry Pi (V8) systems Details: Hador Manor discovered that the DCCP protocol implementation in the Linux kernel improperly handled socket reuse, 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-2020-16119) Jay Shin discovered that the ext4 file system implementation in the Linux kernel did not properly handle directory access with broken indexing, leading to an out-of-bounds read vulnerability. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-14314) David Alan Gilbert discovered that the XFS file system implementation in the Linux kernel did not properly perform metadata validation in some circumstances. A local attacker could use this to cause a denial of service. (CVE-2020-14385) Giuseppe Scrivano discovered that the overlay file system in the Linux kernel did not properly perform permission checks in some situations. A local attacker could possibly use this to bypass intended restrictions and gain read access to restricted files. (CVE-2020-16120) It was discovered that a race condition existed in the hugetlb sysctl implementation in the Linux kernel. A privileged attacker could use this to cause a denial of service (system crash). (CVE-2020-25285) It was discovered that the block layer subsystem in the Linux kernel did not properly handle zero-length requests. A local attacker could use this to cause a denial of service. (CVE-2020-25641) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 20.04 LTS: linux-image-5.4.0-1021-raspi 5.4.0-1021.24 linux-image-5.4.0-1026-kvm 5.4.0-1026.27 linux-image-5.4.0-1028-aws 5.4.0-1028.29 linux-image-5.4.0-1028-gcp 5.4.0-1028.29 linux-image-5.4.0-1028-oracle 5.4.0-1028.29 linux-image-5.4.0-1031-azure 5.4.0-1031.32 linux-image-5.4.0-51-generic 5.4.0-51.56 linux-image-5.4.0-51-generic-lpae 5.4.0-51.56 linux-image-5.4.0-51-lowlatency 5.4.0-51.56 linux-image-aws 5.4.0.1028.29 linux-image-azure 5.4.0.1031.29 linux-image-gcp 5.4.0.1028.36 linux-image-generic 5.4.0.51.54 linux-image-generic-hwe-20.04 5.4.0.51.54 linux-image-generic-lpae 5.4.0.51.54 linux-image-generic-lpae-hwe-20.04 5.4.0.51.54 linux-image-gke 5.4.0.1028.36 linux-image-kvm 5.4.0.1026.24 linux-image-lowlatency 5.4.0.51.54 linux-image-lowlatency-hwe-20.04 5.4.0.51.54 linux-image-oem 5.4.0.51.54 linux-image-oem-osp1 5.4.0.51.54 linux-image-oracle 5.4.0.1028.25 linux-image-raspi 5.4.0.1021.56 linux-image-raspi2 5.4.0.1021.56 linux-image-virtual 5.4.0.51.54 linux-image-virtual-hwe-20.04 5.4.0.51.54 Ubuntu 18.04 LTS: linux-image-5.4.0-1021-raspi 5.4.0-1021.24~18.04.1 linux-image-5.4.0-1028-aws 5.4.0-1028.29~18.04.1 linux-image-5.4.0-1028-gcp 5.4.0-1028.29~18.04.1 linux-image-5.4.0-1028-oracle 5.4.0-1028.29~18.04.1 linux-image-5.4.0-1031-azure 5.4.0-1031.32~18.04.1 linux-image-5.4.0-51-generic 5.4.0-51.56~18.04.1 linux-image-5.4.0-51-generic-lpae 5.4.0-51.56~18.04.1 linux-image-5.4.0-51-lowlatency 5.4.0-51.56~18.04.1 linux-image-aws 5.4.0.1028.13 linux-image-azure 5.4.0.1031.13 linux-image-gcp 5.4.0.1028.16 linux-image-generic-hwe-18.04 5.4.0.51.56~18.04.45 linux-image-generic-lpae-hwe-18.04 5.4.0.51.56~18.04.45 linux-image-lowlatency-hwe-18.04 5.4.0.51.56~18.04.45 linux-image-oracle 5.4.0.1028.12 linux-image-raspi-hwe-18.04 5.4.0.1021.25 linux-image-snapdragon-hwe-18.04 5.4.0.51.56~18.04.45 linux-image-virtual-hwe-18.04 5.4.0.51.56~18.04.45 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/4576-1 CVE-2020-14314, CVE-2020-14385, CVE-2020-16119, CVE-2020-16120, CVE-2020-25285, CVE-2020-25641 Package Information: https://launchpad.net/ubuntu/+source/linux/5.4.0-51.56 https://launchpad.net/ubuntu/+source/linux-aws/5.4.0-1028.29 https://launchpad.net/ubuntu/+source/linux-azure/5.4.0-1031.32 https://launchpad.net/ubuntu/+source/linux-gcp/5.4.0-1028.29 https://launchpad.net/ubuntu/+source/linux-kvm/5.4.0-1026.27 https://launchpad.net/ubuntu/+source/linux-oracle/5.4.0-1028.29 https://launchpad.net/ubuntu/+source/linux-raspi/5.4.0-1021.24 https://launchpad.net/ubuntu/+source/linux-aws-5.4/5.4.0-1028.29~18.04.1 https://launchpad.net/ubuntu/+source/linux-azure-5.4/5.4.0-1031.32~18.04.1 https://launchpad.net/ubuntu/+source/linux-gcp-5.4/5.4.0-1028.29~18.04.1 https://launchpad.net/ubuntu/+source/linux-hwe-5.4/5.4.0-51.56~18.04.1 https://launchpad.net/ubuntu/+source/linux-oracle-5.4/5.4.0-1028.29~18.04.1 https://launchpad.net/ubuntu/+source/linux-raspi-5.4/5.4.0-1021.24~18.04.1