Oracle Linux 6 : kernel (ELSA-2012-0052)

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Synopsis :

The remote Oracle Linux host is missing one or more security updates.

Description :

From Red Hat Security Advisory 2012:0052 :

Updated kernel packages that fix one security issue and three bugs are
now available for for Red Hat Enterprise Linux 6.

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.

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

This update fixes the following security issue :

* It was found that permissions were not checked properly in the Linux
kernel when handling the /proc/[pid]/mem writing functionality. A
local, unprivileged user could use this flaw to escalate their
privileges. Refer to Red Hat Knowledgebase article DOC-69129, linked
to in the References, for further information. (CVE-2012-0056,
Important)

Red Hat would like to thank Jüri Aedla for reporting this issue.

This update fixes the following bugs :

* The RHSA-2011:1849 kernel update introduced a bug in the Linux
kernel scheduler, causing a 'WARNING: at kernel/sched.c:5915
thread_return' message and a call trace to be logged. This message was
harmless, and was not due to any system malfunctions or adverse
behavior. With this update, the WARN_ON_ONCE() call in the scheduler
that caused this harmless message has been removed. (BZ#768288)

* The RHSA-2011:1530 kernel update introduced a regression in the way
the Linux kernel maps ELF headers for kernel modules into kernel
memory. If a third-party kernel module is compiled on a Red Hat
Enterprise Linux system with a kernel prior to RHSA-2011:1530, then
loading that module on a system with RHSA-2011:1530 kernel would
result in corruption of one byte in the memory reserved for the
module. In some cases, this could prevent the module from functioning
correctly. (BZ#769595)

* On some SMP systems the tsc may erroneously be marked as unstable
during early system boot or while the system is under heavy load. A
'Clocksource tsc unstable' message was logged when this occurred. As a
result the system would switch to the slower access, but higher
precision HPET clock.

The 'tsc=reliable' kernel parameter is supposed to avoid this problem
by indicating that the system has a known good clock, however, the
parameter only affected run time checks. A fix has been put in to
avoid the boot time checks so that the TSC remains as the clock for
the duration of system runtime. (BZ#755867)

Users should upgrade to these updated packages, which contain
backported patches to correct these issues. The system must be
rebooted for this update to take effect.

See also :

https://oss.oracle.com/pipermail/el-errata/2012-January/002574.html

Solution :

Update the affected kernel packages.

Risk factor :

Medium / CVSS Base Score : 6.9
(CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C)
CVSS Temporal Score : 6.0
(CVSS2#E:ND/RL:OF/RC:C)
Public Exploit Available : true

Family: Oracle Linux Local Security Checks

Nessus Plugin ID: 68435 ()

Bugtraq ID: 51625

CVE ID: CVE-2012-0056