RHSA-2011:0928 - Security Advisory

Topic

Updated kernel packages that fix multiple security issues and various bugs
are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate
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.

This update fixes the following security issues:

• It was found that the receive hook in the ipip_init() function in the

ipip module, and in the ipgre_init() function in the ip_gre module, could
be called before network namespaces setup is complete. If packets were
received at the time the ipip or ip_gre module was still being loaded into
the kernel, it could cause a denial of service. (CVE-2011-1767,
CVE-2011-1768, Moderate)

• It was found that an mmap() call with the MAP_PRIVATE flag on "/dev/zero"

would create transparent hugepages and trigger a certain robustness check.
A local, unprivileged user could use this flaw to cause a denial of
service. (CVE-2011-2479, Moderate)

This update also fixes various bugs. Documentation for these bug fixes will
be available shortly from the Technical Notes document linked to in the
References section.

Users should upgrade to these updated packages, which contain backported
patches to resolve these issues, and fix the bugs noted in the Technical
Notes. 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/kb/docs/DOC-11259

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 Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.1 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.1 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.1 i386
• Red Hat Virtual Storage Appliance (from RHUI) 6.1 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 702303 - CVE-2011-1767 CVE-2011-1768 kernel: netns vs proto registration ordering
• BZ - 711546 - RHEL6.1 x86_64 HVM guest crashes on AMD host when guest memory size is larger than 8G
• BZ - 712413 - Cannot find the extended attribute of #11 inode after remount
• BZ - 712414 - [RHEL6.1] [Kernel] Panic while running testing
• BZ - 713135 - MLS - cgconfigparser cannot search on /cgroup/ dirs
• BZ - 713458 - intel-iommu: missing flush prior to removing domains + avoid broken vm/si domain unlinking
• BZ - 714190 - System Hang when there is smart error on IBM platform
• BZ - 714761 - CVE-2011-2479 kernel: thp: madvise on top of /dev/zero private mapping can lead to panic

CVEs

• CVE-2011-2479
• CVE-2011-1767
• CVE-2011-1768

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.1_Technical_Notes/kernel.html#RHSA-2011-0928