Ubuntu Security Notices
USN-4211-2

USN-4211-2: Linux kernel (Xenial HWE) vulnerabilities

Publication date

3 December 2019

Overview

Several security issues were fixed in the Linux kernel.

Releases

14.04 LTS

Packages

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). (

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 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

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

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.

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

Ubuntu Release	Package Version
14.04 trusty	linux-image-powerpc-smp-lts-xenial – 4.4.0.170.149
	linux-image-lowlatency-lts-xenial – 4.4.0.170.149
	linux-image-generic-lts-xenial – 4.4.0.170.149
	linux-image-4.4.0-170-generic – 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-lowlatency – 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-generic-lpae-lts-xenial – 4.4.0.170.149
	linux-image-4.4.0-1059-aws – 4.4.0-1059.63
	linux-image-4.4.0-170-generic-lpae – 4.4.0-170.199~14.04.1
	linux-image-powerpc64-emb-lts-xenial – 4.4.0.170.149
	linux-image-4.4.0-170-powerpc-smp – 4.4.0-170.199~14.04.1
	linux-image-powerpc64-smp-lts-xenial – 4.4.0.170.149
	linux-image-aws – 4.4.0.1059.60
	linux-image-4.4.0-170-powerpc-e500mc – 4.4.0-170.199~14.04.1
	linux-image-powerpc-e500mc-lts-xenial – 4.4.0.170.149
	linux-image-virtual-lts-xenial – 4.4.0.170.149

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References

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