Moderate: kernel security, bug fix, and enhancement update

Updated kernel packages that fix multiple security issues, several bugs,
and add various enhancements 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.

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

This update fixes the following security issues:

* Numerous reference count leaks were found in the Linux kernel's block
layer I/O context handling implementation. This could allow a local,
unprivileged user to cause a denial of service. (CVE-2012-0879,
Moderate)

* A flaw was found in the Linux kernel's cifs_lookup() implementation.
POSIX open during lookup should only be supported for regular files. When
non-regular files (for example, a named (FIFO) pipe or other special files)
are opened on lookup, it could cause a denial of service. (CVE-2012-1090,
Moderate)

* It was found that the Linux kernel's register set (regset) common
infrastructure implementation did not check if the required get and set
handlers were initialized. A local, unprivileged user could use this flaw
to cause a denial of service by performing a register set operation with a
ptrace() PTRACE_SETREGSET or PTRACE_GETREGSET request. (CVE-2012-1097,
Moderate)

Red Hat would like to thank H. Peter Anvin for reporting CVE-2012-1097.

This update also fixes several bugs and adds various enhancements.
Documentation for these changes 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 correct these issues, and fix the bugs and add the enhancements
noted in the Technical Notes. The system must be rebooted for this update
to take effect.

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.

789373 - cifs: multiple process stuck waiting for page lock [rhel-6.2.z]
796829 - CVE-2012-0879 kernel: block: CLONE_IO io_context refcounting issues
798293 - CVE-2012-1090 kernel: cifs: dentry refcount leak when opening a FIFO on lookup leads to panic on unmount
799209 - CVE-2012-1097 kernel: regset: Prevent null pointer reference on readonly regsets
802379 - Anomaly in mbind memory map causing Java Hotspot JVM Seg fault with NUMA aware ParallelScavange GC [rhel-6.2.z]

https://www.redhat.com/security/data/cve/CVE-2012-0879.html
https://www.redhat.com/security/data/cve/CVE-2012-1090.html
https://www.redhat.com/security/data/cve/CVE-2012-1097.html
https://access.redhat.com/security/updates/classification/#moderate
https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.2_Technical_Notes/kernel.html#RHSA-2012-0481