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Ubuntu Security Notice USN-4211-2
December 03, 2019

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-4211-1 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.

Zhipeng Xie discovered that an infinite loop could be triggered in the CFS
Linux kernel process scheduler. A local attacker could possibly use this to
cause a denial of service. (CVE-2018-20784)

Nicolas Waisman discovered that the WiFi driver stack in the Linux kernel
did not properly validate SSID lengths. A physically proximate attacker
could use this to cause a denial of service (system crash).
(CVE-2019-17133)

Nicolas Waisman discovered that the Chelsio T4/T5 RDMA Driver for the Linux
kernel performed DMA from a kernel stack. A local attacker could use this
to cause a denial of service (system crash). (CVE-2019-17075)

Update instructions:

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

Ubuntu 14.04 ESM:
  linux-image-4.4.0-1059-aws      4.4.0-1059.63
  linux-image-4.4.0-170-generic   4.4.0-170.199~14.04.1
  linux-image-4.4.0-170-generic-lpae  4.4.0-170.199~14.04.1
  linux-image-4.4.0-170-lowlatency  4.4.0-170.199~14.04.1
  linux-image-4.4.0-170-powerpc-e500mc  4.4.0-170.199~14.04.1
  linux-image-4.4.0-170-powerpc-smp  4.4.0-170.199~14.04.1
  linux-image-4.4.0-170-powerpc64-emb  4.4.0-170.199~14.04.1
  linux-image-4.4.0-170-powerpc64-smp  4.4.0-170.199~14.04.1
  linux-image-aws                 4.4.0.1059.60
  linux-image-generic-lpae-lts-xenial  4.4.0.170.149
  linux-image-generic-lts-xenial  4.4.0.170.149
  linux-image-lowlatency-lts-xenial  4.4.0.170.149
  linux-image-powerpc-e500mc-lts-xenial  4.4.0.170.149
  linux-image-powerpc-smp-lts-xenial  4.4.0.170.149
  linux-image-powerpc64-emb-lts-xenial  4.4.0.170.149
  linux-image-powerpc64-smp-lts-xenial  4.4.0.170.149
  linux-image-virtual-lts-xenial  4.4.0.170.149

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/4211-2
  https://usn.ubuntu.com/4211-1
  CVE-2018-20784, CVE-2019-17075, CVE-2019-17133