=========================================================================
Ubuntu Security Notice USN-4579-1
October 14, 2020

linux, linux-aws, linux-kvm, linux-lts-xenial, linux-raspi2,
linux-snapdragon vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

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 (V8) systems
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

Hador Manor discovered that the DCCP protocol implementation in the Linux
kernel improperly handled socket reuse, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2020-16119)

Wen Xu discovered that the XFS file system in the Linux kernel did not
properly validate inode metadata in some situations. An attacker could use
this to construct a malicious XFS image that, when mounted, could cause a
denial of service (system crash). (CVE-2018-10322)

Jay Shin discovered that the ext4 file system implementation in the Linux
kernel did not properly handle directory access with broken indexing,
leading to an out-of-bounds read vulnerability. A local attacker could use
this to cause a denial of service (system crash). (CVE-2020-14314)

It was discovered that a race condition existed in the hugetlb sysctl
implementation in the Linux kernel. A privileged attacker could use this to
cause a denial of service (system crash). (CVE-2020-25285)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1082-kvm      4.4.0-1082.91
  linux-image-4.4.0-1117-aws      4.4.0-1117.131
  linux-image-4.4.0-1141-raspi2   4.4.0-1141.151
  linux-image-4.4.0-1145-snapdragon  4.4.0-1145.155
  linux-image-4.4.0-193-generic   4.4.0-193.224
  linux-image-4.4.0-193-generic-lpae  4.4.0-193.224
  linux-image-4.4.0-193-lowlatency  4.4.0-193.224
  linux-image-4.4.0-193-powerpc-e500mc  4.4.0-193.224
  linux-image-4.4.0-193-powerpc-smp  4.4.0-193.224
  linux-image-4.4.0-193-powerpc64-emb  4.4.0-193.224
  linux-image-4.4.0-193-powerpc64-smp  4.4.0-193.224
  linux-image-aws                 4.4.0.1117.122
  linux-image-generic             4.4.0.193.199
  linux-image-generic-lpae        4.4.0.193.199
  linux-image-kvm                 4.4.0.1082.80
  linux-image-lowlatency          4.4.0.193.199
  linux-image-powerpc-e500mc      4.4.0.193.199
  linux-image-powerpc-smp         4.4.0.193.199
  linux-image-powerpc64-emb       4.4.0.193.199
  linux-image-powerpc64-smp       4.4.0.193.199
  linux-image-raspi2              4.4.0.1141.141
  linux-image-snapdragon          4.4.0.1145.137
  linux-image-virtual             4.4.0.193.199

Ubuntu 14.04 ESM:
  linux-image-4.4.0-1081-aws      4.4.0-1081.85
  linux-image-4.4.0-193-generic   4.4.0-193.224~14.04.1
  linux-image-4.4.0-193-generic-lpae  4.4.0-193.224~14.04.1
  linux-image-4.4.0-193-lowlatency  4.4.0-193.224~14.04.1
  linux-image-aws                 4.4.0.1081.78
  linux-image-generic-lpae-lts-xenial  4.4.0.193.169
  linux-image-generic-lts-xenial  4.4.0.193.169
  linux-image-lowlatency-lts-xenial  4.4.0.193.169
  linux-image-virtual-lts-xenial  4.4.0.193.169

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/4579-1
  CVE-2018-10322, CVE-2020-14314, CVE-2020-16119, CVE-2020-25285

Package Information:
  https://launchpad.net/ubuntu/+source/linux/4.4.0-193.224
  https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1117.131
  https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1082.91
  https://launchpad.net/ubuntu/+source/linux-raspi2/4.4.0-1141.151
  https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1145.155