Ubuntu 16.04 LTS: USN-4211-1 Critical: Kernel Denial Of Service

ubuntu

December 2, 2019

Several security issues were fixed in the Linux kernel.

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:

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)

Topics Covered

security advisory denial of service ubuntu infinite loop linux kernel

Update Instructions

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1063-kvm      4.4.0-1063.70
  linux-image-4.4.0-1099-aws      4.4.0-1099.110
  linux-image-4.4.0-1126-raspi2   4.4.0-1126.135
  linux-image-4.4.0-1130-snapdragon  4.4.0-1130.138
  linux-image-4.4.0-170-generic   4.4.0-170.199
  linux-image-4.4.0-170-generic-lpae  4.4.0-170.199
  linux-image-4.4.0-170-lowlatency  4.4.0-170.199
  linux-image-4.4.0-170-powerpc-e500mc  4.4.0-170.199
  linux-image-4.4.0-170-powerpc-smp  4.4.0-170.199
  linux-image-4.4.0-170-powerpc64-emb  4.4.0-170.199
  linux-image-4.4.0-170-powerpc64-smp  4.4.0-170.199
  linux-image-aws                 4.4.0.1099.103
  linux-image-generic             4.4.0.170.178
  linux-image-generic-lpae        4.4.0.170.178
  linux-image-kvm                 4.4.0.1063.63
  linux-image-lowlatency          4.4.0.170.178
  linux-image-powerpc-e500mc      4.4.0.170.178
  linux-image-powerpc-smp         4.4.0.170.178
  linux-image-powerpc64-emb       4.4.0.170.178
  linux-image-powerpc64-smp       4.4.0.170.178
  linux-image-raspi2              4.4.0.1126.126
  linux-image-snapdragon          4.4.0.1130.122
  linux-image-virtual             4.4.0.170.178

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.