USN-3676-2: Linux kernel (Xenial HWE) vulnerabilities

11 June 2018

linux-lts-xenial, linux-aws vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 14.04 LTS

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty

Details

USN-3676-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 LTS.

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly handle corrupted meta data in some situations. An attacker could use this to specially craft an ext4 file system that caused a denial of service (system crash) when mounted. (CVE-2018-1092, CVE-2018-1093)

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)

It was discovered that the 802.11 software simulator implementation in the Linux kernel contained a memory leak when handling certain error conditions. A local attacker could possibly use this to cause a denial of service (memory exhaustion). (CVE-2018-8087)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 14.04 LTS
linux-image-4.4.0-1023-aws - 4.4.0-1023.23
linux-image-4.4.0-128-generic - 4.4.0-128.154~14.04.1
linux-image-4.4.0-128-generic-lpae - 4.4.0-128.154~14.04.1
linux-image-4.4.0-128-lowlatency - 4.4.0-128.154~14.04.1
linux-image-4.4.0-128-powerpc-e500mc - 4.4.0-128.154~14.04.1
linux-image-4.4.0-128-powerpc-smp - 4.4.0-128.154~14.04.1
linux-image-4.4.0-128-powerpc64-emb - 4.4.0-128.154~14.04.1
linux-image-4.4.0-128-powerpc64-smp - 4.4.0-128.154~14.04.1
linux-image-aws - 4.4.0.1023.23
linux-image-generic-lpae-lts-xenial - 4.4.0.128.108
linux-image-generic-lts-xenial - 4.4.0.128.108
linux-image-lowlatency-lts-xenial - 4.4.0.128.108
linux-image-powerpc-e500mc-lts-xenial - 4.4.0.128.108
linux-image-powerpc-smp-lts-xenial - 4.4.0.128.108
linux-image-powerpc64-emb-lts-xenial - 4.4.0.128.108
linux-image-powerpc64-smp-lts-xenial - 4.4.0.128.108

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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