USN-3168-1: Linux kernel vulnerabilities

11 January 2017

linux 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 - Linux kernel

Details

Dmitry Vyukov discovered that the KVM implementation in the Linux kernel did not properly initialize the Code Segment (CS) in certain error cases. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2016-9756)

Andrey Konovalov discovered that signed integer overflows existed in the setsockopt() system call when handling the SO_SNDBUFFORCE and SO_RCVBUFFORCE options. A local attacker with the CAP_NET_ADMIN capability could use this to cause a denial of service (system crash or memory corruption). (CVE-2016-9793)

Baozeng Ding discovered a race condition that could lead to a use-after- free in the Advanced Linux Sound Architecture (ALSA) subsystem of the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2016-9794)

Baozeng Ding discovered a double free in the netlink_dump() function in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2016-9806)

Update instructions

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

Ubuntu 14.04 LTS
linux-image-3.13.0-107-generic - 3.13.0-107.154
linux-image-3.13.0-107-generic-lpae - 3.13.0-107.154
linux-image-3.13.0-107-lowlatency - 3.13.0-107.154
linux-image-3.13.0-107-powerpc-e500 - 3.13.0-107.154
linux-image-3.13.0-107-powerpc-e500mc - 3.13.0-107.154
linux-image-3.13.0-107-powerpc-smp - 3.13.0-107.154
linux-image-3.13.0-107-powerpc64-emb - 3.13.0-107.154
linux-image-3.13.0-107-powerpc64-smp - 3.13.0-107.154
linux-image-generic - 3.13.0.107.115
linux-image-generic-lpae - 3.13.0.107.115
linux-image-lowlatency - 3.13.0.107.115
linux-image-powerpc-e500 - 3.13.0.107.115
linux-image-powerpc-e500mc - 3.13.0.107.115
linux-image-powerpc-smp - 3.13.0.107.115
linux-image-powerpc64-emb - 3.13.0.107.115
linux-image-powerpc64-smp - 3.13.0.107.115

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