========================================================================== Ubuntu Security Notice USN-3718-1 July 21, 2018 linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-oem regression ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 18.04 LTS Summary: A regression that caused boot failures was 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-oem: Linux kernel for OEM processors Details: USN-3695-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. Unfortunately, the fix for CVE-2018-1108 introduced a regression where insufficient early entropy prevented services from starting, leading in some situations to a failure to boot, This update addresses the issue. We apologize for the inconvenience. Original advisory details: Jann Horn discovered that the Linux kernel's implementation of random seed data reported that it was in a ready state before it had gathered sufficient entropy. An attacker could use this to expose sensitive information. (CVE-2018-1108) Wen Xu discovered that the ext4 file system implementation in the Linux kernel did not properly initialize the crc32c checksum driver. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1094) It was discovered that the cdrom driver in the Linux kernel contained an incorrect bounds check. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-10940) Wen Xu discovered that the ext4 file system implementation in the Linux kernel did not properly validate xattr sizes. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1095) Jann Horn discovered that the 32 bit adjtimex() syscall implementation for 64 bit Linux kernels did not properly initialize memory returned to user space in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-11508) It was discovered that an information leak vulnerability existed in the floppy driver in the Linux kernel. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-7755) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 18.04 LTS: linux-image-4.15.0-1014-gcp 4.15.0-1014.14 linux-image-4.15.0-1016-aws 4.15.0-1016.16 linux-image-4.15.0-1016-kvm 4.15.0-1016.16 linux-image-4.15.0-1018-azure 4.15.0-1018.18 linux-image-4.15.0-29-generic 4.15.0-29.31 linux-image-4.15.0-29-generic-lpae 4.15.0-29.31 linux-image-4.15.0-29-lowlatency 4.15.0-29.31 linux-image-4.15.0-29-snapdragon 4.15.0-29.31 linux-image-aws 4.15.0.1016.16 linux-image-azure 4.15.0.1018.18 linux-image-gcp 4.15.0.1014.16 linux-image-generic 4.15.0.29.31 linux-image-generic-lpae 4.15.0.29.31 linux-image-gke 4.15.0.1014.16 linux-image-kvm 4.15.0.1016.16 linux-image-lowlatency 4.15.0.29.31 linux-image-oem 4.15.0.1012.14 linux-image-snapdragon 4.15.0.29.31 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/usn/usn-3718-1 https://launchpad.net/bugs/1779827, https://usn.ubuntu.com/usn/usn-3695-1 Package Information: https://launchpad.net/ubuntu/+source/linux/4.15.0-29.31 https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1016.16 https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1018.18 https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1014.14 https://launchpad.net/ubuntu/+source/linux-kvm/4.15.0-1016.16 https://launchpad.net/ubuntu/+source/linux-oem/4.15.0-1012.15