RHSA-2015:1199 - Security Advisory

Topic

Updated kernel packages that fix two security issues and three bugs are now
available for Red Hat Enterprise Linux 6.5 Extended Update Support.

Red Hat Product Security 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.

• It was found that the Linux kernel's implementation of vectored pipe read

and write functionality did not take into account the I/O vectors that were
already processed when retrying after a failed atomic access operation,
potentially resulting in memory corruption due to an I/O vector array
overrun. A local, unprivileged user could use this flaw to crash the system
or, potentially, escalate their privileges on the system. (CVE-2015-1805,
Important)

• A buffer overflow flaw was found in the way the Linux kernel's Intel

AES-NI instructions optimized version of the RFC4106 GCM mode decryption
functionality handled fragmented packets. A remote attacker could use this
flaw to crash, or potentially escalate their privileges on, a system over a
connection with an active AES-GCM mode IPSec security association.
(CVE-2015-3331, Important)

The security impact of the CVE-2015-1805 issue was discovered by Red Hat.

This update also fixes the following bugs:

• Parallel extending direct I/O writes to a file could previously race to update

the size of the file. If executed in an incorrect order, the file size could
move backwards and push a previously completed write beyond the end of the file,
which resulted in losing the write. With this update, file size updates always
execute in appropriate order, thus fixing this bug. (BZ#1218498)

• When the load rose and run queues were busy due to the effects of the

enqueue_entity() function, tasks with large sched_entity.vruntime values could
previously be prevented from using the CPU time. A patch eliminating the
entity_key() function in the sched_fair.c latency value has been backported from
upstream, and all tasks are now provided with fair CPU runtime. (BZ#1219121)

• Previously, running the clock_gettime() function quickly in a loop could

result in a jump back in time. Consequently, programs could behave unexpectedly
when they assumed that clock_getime() returned an equal or greater time in
subsequent calls. With this update, if the time delta between calls is negative,
the clock is no longer updated. As a result, a subsequent call to
clock_gettime() is guaranteed to return a time greater than or equal to a
previous call. (BZ#1219500)

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.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.5 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.5 ppc64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 i386
• Red Hat Enterprise Linux EUS Compute Node 6.5 x86_64
• Red Hat Enterprise Linux Server - AUS 6.5 x86_64
• Red Hat Enterprise Linux Server - TUS 6.5 x86_64

Fixes

• BZ - 1202855 - CVE-2015-1805 kernel: pipe: iovec overrun leading to memory corruption
• BZ - 1213322 - CVE-2015-3331 Kernel: crypto: buffer overruns in RFC4106 implementation using AESNI

CVEs

• CVE-2015-3331
• CVE-2015-1805

References

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