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Ubuntu Security Notice USN-4254-2
January 29, 2020

linux-lts-xenial, linux-aws vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 ESM

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

USN-4254-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu
14.04 ESM.

It was discovered that the Linux kernel did not properly clear data
structures on context switches for certain Intel graphics processors. A
local attacker could use this to expose sensitive information.
(CVE-2019-14615)

It was discovered that a race condition existed in the Virtual Video Test
Driver in the Linux kernel. An attacker with write access to /dev/video0 on
a system with the vivid module loaded could possibly use this to gain
administrative privileges. (CVE-2019-18683)

It was discovered that the btrfs file system in the Linux kernel did not
properly validate metadata, leading to a NULL pointer dereference. An
attacker could use this to specially craft a file system image that, when
mounted, could cause a denial of service (system crash). (CVE-2019-18885)

It was discovered that multiple memory leaks existed in the Marvell WiFi-Ex
Driver for the Linux kernel. A local attacker could possibly use this to
cause a denial of service (kernel memory exhaustion). (CVE-2019-19057)

It was discovered that the crypto subsystem in the Linux kernel did not
properly deallocate memory in certain error conditions. A local attacker
could use this to cause a denial of service (kernel memory exhaustion).
(CVE-2019-19062)

It was discovered that the Realtek rtlwifi USB device driver in the Linux
kernel did not properly deallocate memory in certain error conditions. A
local attacker could possibly use this to cause a denial of service (kernel
memory exhaustion). (CVE-2019-19063)

Dan Carpenter discovered that the AppleTalk networking subsystem of the
Linux kernel did not properly handle certain error conditions, leading to a
NULL pointer dereference. A local attacker could use this to cause a denial
of service (system crash). (CVE-2019-19227)

It was discovered that the KVM hypervisor implementation in the Linux
kernel did not properly handle ioctl requests to get emulated CPUID
features. An attacker with access to /dev/kvm could use this to cause a
denial of service (system crash). (CVE-2019-19332)

It was discovered that the B2C2 FlexCop USB device driver in the Linux
kernel did not properly validate device metadata. A physically proximate
attacker could use this to cause a denial of service (system crash).
(CVE-2019-15291)

Update instructions:

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

Ubuntu 14.04 ESM:
  linux-image-4.4.0-1061-aws      4.4.0-1061.65
  linux-image-4.4.0-173-generic   4.4.0-173.203~14.04.1
  linux-image-4.4.0-173-generic-lpae  4.4.0-173.203~14.04.1
  linux-image-4.4.0-173-lowlatency  4.4.0-173.203~14.04.1
  linux-image-4.4.0-173-powerpc-e500mc  4.4.0-173.203~14.04.1
  linux-image-4.4.0-173-powerpc-smp  4.4.0-173.203~14.04.1
  linux-image-4.4.0-173-powerpc64-emb  4.4.0-173.203~14.04.1
  linux-image-4.4.0-173-powerpc64-smp  4.4.0-173.203~14.04.1
  linux-image-aws                 4.4.0.1061.62
  linux-image-generic-lpae-lts-xenial  4.4.0.173.152
  linux-image-generic-lts-xenial  4.4.0.173.152
  linux-image-lowlatency-lts-xenial  4.4.0.173.152
  linux-image-powerpc-e500mc-lts-xenial  4.4.0.173.152
  linux-image-powerpc-smp-lts-xenial  4.4.0.173.152
  linux-image-powerpc64-emb-lts-xenial  4.4.0.173.152
  linux-image-powerpc64-smp-lts-xenial  4.4.0.173.152
  linux-image-virtual-lts-xenial  4.4.0.173.152

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/4254-2
  https://usn.ubuntu.com/4254-1
  CVE-2019-14615, CVE-2019-15291, CVE-2019-18683, CVE-2019-18885,
  CVE-2019-19057, CVE-2019-19062, CVE-2019-19063, CVE-2019-19227,
  CVE-2019-19332