==========================================================================
Ubuntu Security Notice USN-3631-1
April 24, 2018

linux, linux-aws, linux-kvm, 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-kvm: Linux kernel for cloud environments
- linux-raspi2: Linux kernel for Raspberry Pi 2
- linux-snapdragon: Linux kernel for Snapdragon processors

Details:

It was discovered that a buffer overread vulnerability existed in the
keyring subsystem of the Linux kernel. A local attacker could possibly use
this to expose sensitive information (kernel memory). (CVE-2017-13305)

It was discovered that the DM04/QQBOX USB driver in the Linux kernel did
not properly handle device attachment and warm-start. A physically
proximate attacker could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2017-16538)

Luo Quan and Wei Yang discovered that a race condition existed in the
Advanced Linux Sound Architecture (ALSA) subsystem of the Linux kernel when
handling ioctl()s. A local attacker could use this to cause a denial of
service (system deadlock). (CVE-2018-1000004)

Wang Qize discovered that an information disclosure vulnerability existed
in the SMBus driver for ACPI Embedded Controllers in the Linux kernel. A
local attacker could use this to expose sensitive information (kernel
pointer addresses). (CVE-2018-5750)

ee3/4ePS discovered that a race condition existed in the Advanced Linux
Sound Architecture (ALSA) subsystem of the Linux kernel that could lead to
a use-after-free or an out-of-bounds buffer access. A local attacker with
access to /dev/snd/seq could use this to cause a denial of service (system
crash) or possibly execute arbitrary code. (CVE-2018-7566)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1021-kvm      4.4.0-1021.26
  linux-image-4.4.0-1055-aws      4.4.0-1055.64
  linux-image-4.4.0-1087-raspi2   4.4.0-1087.95
  linux-image-4.4.0-1090-snapdragon  4.4.0-1090.95
  linux-image-4.4.0-121-generic   4.4.0-121.145
  linux-image-4.4.0-121-generic-lpae  4.4.0-121.145
  linux-image-4.4.0-121-lowlatency  4.4.0-121.145
  linux-image-4.4.0-121-powerpc-e500mc  4.4.0-121.145
  linux-image-4.4.0-121-powerpc-smp  4.4.0-121.145
  linux-image-4.4.0-121-powerpc64-emb  4.4.0-121.145
  linux-image-4.4.0-121-powerpc64-smp  4.4.0-121.145
  linux-image-aws                 4.4.0.1055.57
  linux-image-generic             4.4.0.121.127
  linux-image-generic-lpae        4.4.0.121.127
  linux-image-kvm                 4.4.0.1021.20
  linux-image-lowlatency          4.4.0.121.127
  linux-image-powerpc-e500mc      4.4.0.121.127
  linux-image-powerpc-smp         4.4.0.121.127
  linux-image-powerpc64-emb       4.4.0.121.127
  linux-image-powerpc64-smp       4.4.0.121.127
  linux-image-raspi2              4.4.0.1087.87
  linux-image-snapdragon          4.4.0.1090.82

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:
  https://usn.ubuntu.com/usn/usn-3631-1
  CVE-2017-13305, CVE-2017-16538, CVE-2018-1000004, CVE-2018-5750,
  CVE-2018-7566

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.4.0-121.145
  https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1055.64
  https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1021.26
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1087.95
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1090.95