USN-3880-2: Linux kernel (Trusty HWE) vulnerabilities

USN-3880-1 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. It was discovered that the CIFS client implementation in the Linux kernel did not properly handle setup negotiation during session recovery, leading to a NULL pointer exception. An attacker could use this to create a malicious CIFS server that caused a denial of service (client system crash). (CVE-2018-1066) Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. (CVE-2018-17972) Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when completing, potentially leaving access to a physical page after it has been released to the page allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive information, or possibly execute arbitrary code. (CVE-2018-18281) It was discovered that the socket implementation in the Linux kernel contained a type confusion error that could lead to memory corruption. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-9568)