RHSA-2014:0900 - Security Advisory

Topic

Updated kernel packages that fix three security issues and one bug are now
available for Red Hat Enterprise Linux 6.4 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 futex subsystem handled

the requeuing of certain Priority Inheritance (PI) futexes. A local,
unprivileged user could use this flaw to escalate their privileges on the
system. (CVE-2014-3153, Important)

• 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.

Red Hat would like to thank Kees Cook of Google for reporting
CVE-2014-3153, and Matthew Daley for reporting CVE-2014-1737 and
CVE-2014-1738. Google acknowledges Pinkie Pie as the original reporter of
CVE-2014-3153.

This update also fixes the following bug:

• A previous change that introduced global clock updates caused guest

machines to boot slowly when the host Time Stamp Counter (TSC) was marked
as unstable. The slow down increased with the number of vCPUs allocated.
To resolve this problem, a patch has been applied to limit the rate of the
global clock updates. (BZ#1102253)

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/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 6.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.4 i386
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.4 ppc64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.4 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.4 i386
• Red Hat Gluster Storage Server for On-premise 2.1 x86_64
• Red Hat Storage for Public Cloud (via RHUI) 2.1 x86_64
• Red Hat Enterprise Linux EUS Compute Node 6.4 x86_64
• Red Hat Enterprise Linux Server - AUS 6.4 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.4 s390x

Fixes

• BZ - 1094299 - CVE-2014-1737 CVE-2014-1738 kernel: block: floppy: privilege escalation via FDRAWCMD floppy ioctl command
• BZ - 1103626 - CVE-2014-3153 kernel: futex: pi futexes requeue issue

CVEs

• CVE-2014-1737
• CVE-2014-1738
• CVE-2014-3153

References

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