==========================================================================
Ubuntu Security Notice USN-3776-1
October 01, 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:

Jann Horn discovered that the vmacache subsystem did not properly handle
sequence number overflows, leading to a use-after-free vulnerability. A
local attacker could use this to cause a denial of service (system crash)
or execute arbitrary code. (CVE-2018-17182)

It was discovered that the paravirtualization implementation in the Linux
kernel did not properly handle some indirect calls, reducing the
effectiveness of Spectre v2 mitigations for paravirtual guests. A local
attacker could use this to expose sensitive information. (CVE-2018-15594)

It was discovered that microprocessors utilizing speculative execution and
prediction of return addresses via Return Stack Buffer (RSB) may allow
unauthorized memory reads via sidechannel attacks. An attacker could use
this to expose sensitive information. (CVE-2018-15572)

It was discovered that a NULL pointer dereference could be triggered in the
OCFS2 file system implementation in the Linux kernel. A local attacker
could use this to cause a denial of service (system crash).
(CVE-2017-18216)

It was discovered that a race condition existed in the raw MIDI driver for
the Linux kernel, leading to a double free vulnerability. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2018-10902)

It was discovered that a stack-based buffer overflow existed in the iSCSI
target implementation of the Linux kernel. A remote attacker could use this
to cause a denial of service (system crash). (CVE-2018-14633)

It was discovered that the YUREX USB device driver for the Linux kernel did
not properly restrict user space reads or writes. A physically proximate
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2018-16276)

It was discovered that a memory leak existed in the IRDA subsystem of the
Linux kernel. A local attacker could use this to cause a denial of service
(kernel memory exhaustion). (CVE-2018-6554)

It was discovered that a use-after-free vulnerability existed in the IRDA
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-2018-6555)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1035-kvm      4.4.0-1035.41
  linux-image-4.4.0-1069-aws      4.4.0-1069.79
  linux-image-4.4.0-1098-raspi2   4.4.0-1098.106
  linux-image-4.4.0-1102-snapdragon  4.4.0-1102.107
  linux-image-4.4.0-137-generic   4.4.0-137.163
  linux-image-4.4.0-137-generic-lpae  4.4.0-137.163
  linux-image-4.4.0-137-lowlatency  4.4.0-137.163
  linux-image-4.4.0-137-powerpc-e500mc  4.4.0-137.163
  linux-image-4.4.0-137-powerpc-smp  4.4.0-137.163
  linux-image-4.4.0-137-powerpc64-emb  4.4.0-137.163
  linux-image-4.4.0-137-powerpc64-smp  4.4.0-137.163
  linux-image-aws                 4.4.0.1069.71
  linux-image-generic             4.4.0.137.143
  linux-image-generic-lpae        4.4.0.137.143
  linux-image-kvm                 4.4.0.1035.34
  linux-image-lowlatency          4.4.0.137.143
  linux-image-powerpc-e500mc      4.4.0.137.143
  linux-image-powerpc-smp         4.4.0.137.143
  linux-image-powerpc64-emb       4.4.0.137.143
  linux-image-powerpc64-smp       4.4.0.137.143
  linux-image-raspi2              4.4.0.1098.98
  linux-image-snapdragon          4.4.0.1102.94

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-3776-1
  CVE-2017-18216, CVE-2018-10902, CVE-2018-14633, CVE-2018-15572,
  CVE-2018-15594, CVE-2018-16276, CVE-2018-17182, CVE-2018-6554,
  CVE-2018-6555

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.4.0-137.163
  https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1069.79
  https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1035.41
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1098.106
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1102.107