Ubuntu Security Notice 3234-2 – USN-3234-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 LTS. Ralf Spenneberg discovered that the ext4 implementation in the Linux kernel did not properly validate meta block groups. An attacker with physical access could use this to specially craft an ext4 image that causes a denial of service. Various other issues were also addressed.