USN-2947-2: Linux kernel (Wily HWE) vulnerabilities

6 April 2016

linux-lts-wily vulnerabilities

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

  • Ubuntu 14.04 LTS

Summary

Several security issues were fixed in the kernel.

Software Description

  • linux-lts-wily - Linux hardware enablement kernel from Wily for Trusty

Details

Ralf Spenneberg discovered that the usbvision driver in the Linux kernel did not properly sanity check the interfaces and endpoints reported by the device. An attacker with physical access could cause a denial of service (system crash). (CVE-2015-7833)

Venkatesh Pottem discovered a use-after-free vulnerability in the Linux kernel’s CXGB3 driver. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2015-8812)

Xiaofei Rex Guo discovered a timing side channel vulnerability in the Linux Extended Verification Module (EVM). An attacker could use this to affect system integrity. (CVE-2016-2085)

It was discovered that the extended Berkeley Packet Filter (eBPF) implementation in the Linux kernel did not correctly compute branch offsets for backward jumps after ctx expansion. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2016-2383)

David Herrmann discovered that the Linux kernel incorrectly accounted file descriptors to the original opener for in-flight file descriptors sent over a unix domain socket. A local attacker could use this to cause a denial of service (resource exhaustion). (CVE-2016-2550)

It was discovered that the Linux kernel did not enforce limits on the amount of data allocated to buffer pipes. A local attacker could use this to cause a denial of service (resource exhaustion). (CVE-2016-2847)

Update instructions

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

Ubuntu 14.04 LTS
linux-image-4.2.0-35-generic - 4.2.0-35.40~14.04.1
linux-image-4.2.0-35-generic-lpae - 4.2.0-35.40~14.04.1
linux-image-4.2.0-35-lowlatency - 4.2.0-35.40~14.04.1
linux-image-4.2.0-35-powerpc-e500mc - 4.2.0-35.40~14.04.1
linux-image-4.2.0-35-powerpc-smp - 4.2.0-35.40~14.04.1
linux-image-4.2.0-35-powerpc64-emb - 4.2.0-35.40~14.04.1
linux-image-4.2.0-35-powerpc64-smp - 4.2.0-35.40~14.04.1

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