RHSA-2014:0772 - Security Advisory

Topic

Updated kernel packages that fix three security issues and two bugs are now
available for Red Hat Enterprise Linux 5.9 Extended Update Support.

The Red Hat Security Response Team has rated this update as having
Important security impact. Common Vulnerability Scoring System (CVSS) base
scores, which give detailed severity ratings, are available for each
vulnerability from the CVE links in the References section.

Description

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

• A flaw was found in the way the Linux kernel's floppy driver handled user

space provided data in certain error code paths while processing FDRAWCMD
IOCTL commands. A local user with write access to /dev/fdX could use this
flaw to free (using the kfree() function) arbitrary kernel memory.
(CVE-2014-1737, Important)

• It was found that the Linux kernel's floppy driver leaked internal kernel

memory addresses to user space during the processing of the FDRAWCMD IOCTL
command. A local user with write access to /dev/fdX could use this flaw to
obtain information about the kernel heap arrangement. (CVE-2014-1738, Low)

Note: A local user with write access to /dev/fdX could use these two flaws
(CVE-2014-1737 in combination with CVE-2014-1738) to escalate their
privileges on the system.

• A flaw was found in the way the Linux kernel's TCP/IP protocol suite

implementation handled TCP packets with both the SYN and FIN flags set.
A remote attacker could use this flaw to consume an excessive amount of
resources on the target system, potentially resulting in a denial of
service. (CVE-2012-6638, Moderate)

Red Hat would like to thank Matthew Daley for reporting CVE-2014-1737 and
CVE-2014-1738.

This update also fixes the following bugs:

• While under heavy load, some Fibre Channel storage devices, such as

Hitachi and HP Open-V series, can send a logout (LOGO) message to the host
system. However, due to a bug in the lpfc driver, this could result in a
loss of active paths to the storage and the paths could not be recovered
without manual intervention. This update corrects the lpfc driver to ensure
automatic recovery of the lost paths to the storage in this scenario.
(BZ#1096060)

• A bug in the futex system call could result in an overflow when passing a

very large positive timeout. As a consequence, the FUTEX_WAIT operation did
not work as intended and the system call was timing out immediately.
A backported patch fixes this bug by limiting very large positive timeouts
to the maximal supported value. (BZ#1091831)

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. The system must be
rebooted for this update to take effect.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not
use "rpm -Uvh" as that will remove the running kernel binaries from
your system. You may use "rpm -e" to remove old kernels after
determining that the new kernel functions properly on your system.

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.9 i386
• Red Hat Enterprise Linux Server - AUS 5.9 x86_64
• Red Hat Enterprise Linux Server - AUS 5.9 ia64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.9 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.9 ppc
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 i386
• Red Hat Enterprise Linux Server - AUS 5.9 i386

Fixes

• BZ - 1066055 - CVE-2012-6638 Kernel: net: tcp: potential DoS via SYN+FIN messages
• BZ - 1094299 - CVE-2014-1737 CVE-2014-1738 kernel: block: floppy: privilege escalation via FDRAWCMD floppy ioctl command

CVEs

• CVE-2012-6638
• CVE-2014-1737
• CVE-2014-1738

References

• https://access.redhat.com/security/updates/classification/#important