[El-errata] New updates available via Ksplice (ELSA-2012-2048)

[Errata Announcements for Oracle Linux]

Synopsis: ELSA-2012-2048 can now be patched using Ksplice
CVEs: CVE-2012-2100 CVE-2012-4444 CVE-2012-4565

Users with Oracle Linux Premier Support can now use Ksplice to patch
against the latest Oracle Security Advisory, ELSA-2012-2048.

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-2012-4565: Divide by zero in TCP congestion control Algorithm.

The TCP Illinois congestion control algorithm does not correctly handle a
zero number of RTTs when reading TCP stats, leading to a divide-by-zero
and kernel panic. A remote attacker could potentially use this flaw to
cause a remote denial of service.


* CVE-2012-2100: Divide-by-zero mounting an ext4 filesystem.

The sanity check added in the original CVE-2009-4307 fix relied on undefined
compiler behaviour, which meant that it worked only on specific architectures
and didn't work on x86 for example.

This fix replaces the check with a standards compliant check which works on
all architectures.


* CVE-2012-4444: Prohibit reassembling IPv6 fragments when some data overlaps.

Accepting overlapping fragmented IPv6 packets can lead to OS fingerprinting,
IDS/IPS insertion/evasion, firewall evasion.

SUPPORT

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