RHSA-2013:0661 - Security Advisory

Topic

Updated kernel packages that fix one security issue and one bug are now
available for Red Hat Enterprise Linux 6.1 Extended Update Support.

The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from the
CVE link 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 issue:

• A race condition was found in the way the Linux kernel's ptrace

implementation handled PTRACE_SETREGS requests when the debuggee was woken
due to a SIGKILL signal instead of being stopped. A local, unprivileged
user could use this flaw to escalate their privileges. (CVE-2013-0871,
Important)

This update also fixes the following bug:

• Due to the incorrect validation of a pointer dereference in the

d_validate() function, running a command such as ls or find on the
MultiVersion File System (MVFS), used by IBM Rational ClearCase, for
example, could trigger a kernel panic. This update modifies d_validate() to
verify the parent-child dentry relationship by searching through the
parent's d_child list. The kernel no longer panics in this situation.
(BZ#915580)

Users should upgrade to these updated packages, which contain backported
patches to resolve 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 6.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.1 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.1 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.1 ppc64
• 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

Fixes

• BZ - 911937 - CVE-2013-0871 kernel: race condition with PTRACE_SETREGS

CVEs

• CVE-2013-0871

References

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