USN-3470-2: Linux kernel (Trusty HWE) vulnerabilities

USN-3470-1 fixed vulnerabilities in the Linux kernel for Ubuntu 14.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 14.04 LTS for Ubuntu 12.04 ESM. Qian Zhang discovered a heap-based buffer overflow in the tipcmsgbuild() function in the Linux kernel. A local attacker could use to cause a denial of service (system crash) or possibly execute arbitrary code with administrative privileges. (CVE-2016-8632) Dmitry Vyukov discovered that a race condition existed in the timerfd subsystem of the Linux kernel when handling mightcancel queuing. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-10661) It was discovered that the Flash-Friendly File System (f2fs) implementation in the Linux kernel did not properly validate superblock metadata. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-10662, CVE-2017-10663) Anthony Perard discovered that the Xen virtual block driver did not properly initialize some data structures before passing them to user space. A local attacker in a guest VM could use this to expose sensitive information from the host OS or other guest VMs. (CVE-2017-10911) It was discovered that a use-after-free vulnerability existed in the POSIX message queue implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-11176) Dave Chinner discovered that the XFS filesystem did not enforce that the realtime inode flag was settable only on filesystems on a realtime device. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-14340)