[El-errata] New updates available via Ksplice (RHSA-2016:0715)

[Errata Announcements for Oracle Linux]

Synopsis: RHSA-2016:0715 can now be patched using Ksplice
CVEs: CVE-2015-5157 CVE-2015-8767

Users with Oracle Linux Premier Support can now use Ksplice to patch
against the latest Oracle kernel update, RHSA-2016:0715.

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack on EL 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-2015-5157: Disable modification of LDT by userspace processes.

The seldom-used modify_ldt syscall allowing processes to modify their local
descriptor table has several vulnerabilities allowing local unprivileged
users to elevate privileges.

This update disables by default the modify_ldt syscall and introduces a new
sysctl 'ksplice_modify_ldt' to allow administrators to re-enable it.
Re-enabling the syscall will make the machine vulnerable.

To re-enable modify_ldt, run the following command as root:

  sysctl ksplice_modify_ldt=1

To disable, run:

  sysctl ksplice_modify_ldt=0

This mitigates CVE-2015-3290, CVE-2015-3291 and CVE-2015-5157.


* CVE-2015-8767: Denial-of-service in SCTP heartbeat timeout.

Incorrect locking when accepting an SCTP connection during the 4-way
handshake could result in deadlock.  A local user could use this flaw to
block SCTP connections.

SUPPORT

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