[Ksplice][Ubuntu-18.04-Updates] New Ksplice updates for Ubuntu 18.04 Bionic (USN-3981-1)

[Oracle Ksplice]

Synopsis: USN-3981-1 can now be patched using Ksplice
CVEs: CVE-2018-12126 CVE-2018-12127 CVE-2018-12130 CVE-2019-11091 CVE-2019-11477 CVE-2019-11478 CVE-2019-11479

Systems running Ubuntu 18.04 Bionic can now use Ksplice to patch
against the latest Ubuntu Security Notice, USN-3981-1.

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack running Ubuntu 18.04
Bionic install these updates.

On systems that have "autoinstall = yes" in /etc/uptrack/uptrack.conf,
these updates will be installed automatically and you do not need to
take any action.

Alternatively, you can install these updates by running:

# /usr/sbin/uptrack-upgrade -y


DESCRIPTION

* CVE-2019-11477, CVE-2019-11478: Remote Denial-of-service in TCP stack.

A number of errors in the TCP stack could result in a remotely
triggerable denial of service on links with a small Maximum Segment Size
(MSS).  A remote user could use a maliciously crafted TCP stream to
either panic the system or exhaust resources.


* CVE-2019-11479: Remote Denial-of-service in TCP stack.

An error in the TCP stack could result in a remotely triggerable
denial-of-service on links with a small Maximum Segment Size (MSS).
A remote user could use a maliciously crafted TCP stream to exhaust
resources.

A new sysctl, ksplice_net_ipv4.tcp_min_snd_mss can be used to adjust
the minimum Maximum Segment Size and defaults to 48 bytes.


* KPTI enablement for Ksplice.




* CVE-2019-11091, CVE-2018-12126, CVE-2018-12130, CVE-2018-12127: Microarchitectural Data Sampling.

A hardware vulnerability on various Intel x86 processors can allow a process to
speculatively access privileged information stored in CPU microarchitectural
buffers. A local user or guest VM could use this flaw to learn information
about the host kernel or hypervisor and use this to facilitate a further
attack.

Updated microcode is required for the mitigation to be effective, please see
the output of /sys/devices/system/cpu/vulnerabilities/mds to determine whether
the microcode supports the mitigation.

This update does not mitigate the vulnerability when SMT is in use. SMT can be
disabled with the following command:

echo off > /sys/devices/system/cpu/smt/control

SUPPORT

Ksplice support is available at ksplice-support_ww at oracle.com.