[Ksplice][Virtuozzo 4.7 Updates] New Ksplice updates for Virtuozzo 4.7 or OpenVZ on RHEL 6 (2.6.32-042stab139.1)

[Oracle Ksplice]

Synopsis: 2.6.32-042stab139.1 can now be patched using Ksplice
CVEs: CVE-2019-11477 CVE-2019-11478 CVE-2019-11479 CVE-2019-3896

Systems running Virtuozzo 4.7 or the OpenVZ RHEL 6 kernel can now use
Ksplice to patch against the latest Parallels Virtuozzo Containers 4.7
kernel security update, 2.6.32-042stab139.1.

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack running Virtuozzo 4.7
or OpenVZ on RHEL 6 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, CVE-2019-11479: 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.

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


* CVE-2019-3896: Double-free in kernel integer ID management library.

The 'idr' kernel library for integer ID management behaves incorrectly
when its internal tree structure becomes too large, resulting in a
double-free of some of its internal members. An unprivileged user could
exploit this behavior to cause a kernel crash and denial-of-service.

SUPPORT

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