========================================================================== Ubuntu Security Notice USN-3507-2 December 08, 2017 linux-gcp vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 16.04 LTS Summary: Several security issues were fixed in the Linux kernel. Software Description: - linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems Details: Mohamed Ghannam discovered that a use-after-free vulnerability existed in the Netlink subsystem (XFRM) in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-16939) It was discovered that the Linux kernel did not properly handle copy-on- write of transparent huge pages. A local attacker could use this to cause a denial of service (application crashes) or possibly gain administrative privileges. (CVE-2017-1000405) Fan Wu, Haoran Qiu, and Shixiong Zhao discovered that the associative array implementation in the Linux kernel sometimes did not properly handle adding a new entry. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-12193) Eric Biggers discovered that the key management subsystem in the Linux kernel did not properly restrict adding a key that already exists but is uninstantiated. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-15299) It was discovered that a null pointer dereference error existed in the PowerPC KVM implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-15306) Eric Biggers discovered a race condition in the key management subsystem of the Linux kernel around keys in a negative state. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-15951) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 16.04 LTS: linux-image-4.13.0-1002-gcp 4.13.0-1002.5 linux-image-gcp 4.13.0.1002.4 linux-image-gke 4.13.0.1002.4 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://www.ubuntu.com/usn/usn-3507-2 https://www.ubuntu.com/usn/usn-3507-1 CVE-2017-1000405, CVE-2017-12193, CVE-2017-15299, CVE-2017-15306, CVE-2017-15951, CVE-2017-16939 Package Information: https://launchpad.net/ubuntu/+source/linux-gcp/4.13.0-1002.5