USN-3405-1: Linux kernel vulnerabilities

28 August 2017

linux, linux-aws, linux-gke, linux-raspi2, linux-snapdragon 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 - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-gke - Linux kernel for Google Container Engine (GKE) systems
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-snapdragon - Linux kernel for Snapdragon processors

Details

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)

Huang Weller discovered that the ext4 filesystem implementation in the Linux kernel mishandled a needs-flushing-before-commit list. A local attacker could use this to expose sensitive information. (CVE-2017-7495)

It was discovered that a buffer overflow existed in the Broadcom FullMAC WLAN driver in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-7541)

It was discovered that the Linux kernel did not honor the UEFI secure boot mode when performing a kexec operation. A local attacker could use this to bypass secure boot restrictions. (CVE-2015-7837)

Update instructions

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

Ubuntu 16.04 LTS
linux-image-4.4.0-1028-gke - 4.4.0-1028.28
linux-image-4.4.0-1032-aws - 4.4.0-1032.41
linux-image-4.4.0-1071-raspi2 - 4.4.0-1071.79
linux-image-4.4.0-1073-snapdragon - 4.4.0-1073.78
linux-image-4.4.0-93-generic - 4.4.0-93.116
linux-image-4.4.0-93-generic-lpae - 4.4.0-93.116
linux-image-4.4.0-93-lowlatency - 4.4.0-93.116
linux-image-4.4.0-93-powerpc-e500mc - 4.4.0-93.116
linux-image-4.4.0-93-powerpc-smp - 4.4.0-93.116
linux-image-4.4.0-93-powerpc64-emb - 4.4.0-93.116
linux-image-4.4.0-93-powerpc64-smp - 4.4.0-93.116
linux-image-aws - 4.4.0.1032.34
linux-image-generic - 4.4.0.93.98
linux-image-generic-lpae - 4.4.0.93.98
linux-image-gke - 4.4.0.1028.29
linux-image-lowlatency - 4.4.0.93.98
linux-image-powerpc-smp - 4.4.0.93.98
linux-image-powerpc64-emb - 4.4.0.93.98
linux-image-powerpc64-smp - 4.4.0.93.98
linux-image-raspi2 - 4.4.0.1071.71
linux-image-snapdragon - 4.4.0.1073.65

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