USN-3265-1: Linux kernel vulnerabilities

25 April 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 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 flaw existed in the filesystem encryption subsystem in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-7374)

Andrey Konovalov discovered an out-of-bounds access in the IPv6 Generic Routing Encapsulation (GRE) tunneling implementation in the Linux kernel. An attacker could use this to possibly expose sensitive information. (CVE-2017-5897)

Andrey Konovalov discovered that the IPv4 implementation in the Linux kernel did not properly handle invalid IP options in some situations. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2017-5970)

Gareth Evans discovered that the shm IPC subsystem in the Linux kernel did not properly restrict mapping page zero. A local privileged attacker could use this to execute arbitrary code. (CVE-2017-5669)

Alexander Popov discovered that a race condition existed in the Stream Control Transmission Protocol (SCTP) implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-5986)

Dmitry Vyukov discovered that the Linux kernel did not properly handle TCP packets with the URG flag. A remote attacker could use this to cause a denial of service. (CVE-2017-6214)

Andrey Konovalov discovered that the LLC subsytem in the Linux kernel did not properly set up a destructor in certain situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-6345)

It was discovered that a race condition existed in the AF_PACKET handling code in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-6346)

Andrey Konovalov discovered that the IP layer in the Linux kernel made improper assumptions about internal data layout when performing checksums. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-6347)

Dmitry Vyukov discovered race conditions in the Infrared (IrDA) subsystem in the Linux kernel. A local attacker could use this to cause a denial of service (deadlock). (CVE-2017-6348)

Update instructions

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

Ubuntu 16.04 LTS
linux-image-4.4.0-1012-gke - 4.4.0-1012.12
linux-image-4.4.0-1016-aws - 4.4.0-1016.25
linux-image-4.4.0-1054-raspi2 - 4.4.0-1054.61
linux-image-4.4.0-1057-snapdragon - 4.4.0-1057.61
linux-image-4.4.0-75-generic - 4.4.0-75.96
linux-image-4.4.0-75-generic-lpae - 4.4.0-75.96
linux-image-4.4.0-75-lowlatency - 4.4.0-75.96
linux-image-4.4.0-75-powerpc-e500mc - 4.4.0-75.96
linux-image-4.4.0-75-powerpc-smp - 4.4.0-75.96
linux-image-4.4.0-75-powerpc64-smp - 4.4.0-75.96
linux-image-aws - 4.4.0.1016.19
linux-image-generic - 4.4.0.75.81
linux-image-generic-lpae - 4.4.0.75.81
linux-image-gke - 4.4.0.1012.14
linux-image-lowlatency - 4.4.0.75.81
linux-image-powerpc-e500mc - 4.4.0.75.81
linux-image-powerpc-smp - 4.4.0.75.81
linux-image-powerpc64-smp - 4.4.0.75.81
linux-image-raspi2 - 4.4.0.1054.55
linux-image-snapdragon - 4.4.0.1057.50

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