Synopsis

Important: kernel security and bug fix update

Type/Severity

Security Advisory: Important

Topic

Updated kernel packages that fix several security issues and bugs are
now available for Red Hat Enterprise Linux 7.

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.

Security fixes:

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

subsystem handled PIT (Programmable Interval Timer) emulation. A guest user
who has access to the PIT I/O ports could use this flaw to crash the host.
(CVE-2014-3611, Important)

• A NULL pointer dereference flaw was found in the way the Linux kernel's

Stream Control Transmission Protocol (SCTP) implementation handled
simultaneous connections between the same hosts. A remote attacker could
use this flaw to crash the system. (CVE-2014-5077, Important)

• It was found that the Linux kernel's KVM subsystem did not handle the VM

exits gracefully for the invept (Invalidate Translations Derived from EPT)
and invvpid (Invalidate Translations Based on VPID) instructions. On hosts
with an Intel processor and invept/invppid VM exit support, an unprivileged
guest user could use these instructions to crash the guest. (CVE-2014-3645,
CVE-2014-3646, Moderate)

• A use-after-free flaw was found in the way the Linux kernel's Advanced

Linux Sound Architecture (ALSA) implementation handled user controls. A
local, privileged user could use this flaw to crash the system.
(CVE-2014-4653, Moderate)

Red Hat would like to thank Lars Bull of Google for reporting
CVE-2014-3611, and the Advanced Threat Research team at Intel Security for
reporting CVE-2014-3645 and CVE-2014-3646.

Bug fixes:

• A known issue that could prevent Chelsio adapters using the cxgb4 driver

from being initialized on IBM POWER8 systems has been fixed. These
adapters can now be used on IBM POWER8 systems as expected. (BZ#1130548)

• When bringing a hot-added CPU online, the kernel did not initialize a

CPU mask properly, which could result in a kernel panic. This update
corrects the bug by ensuring that the CPU mask is properly initialized and
the correct NUMA node selected. (BZ#1134715)

• The kernel could fail to bring a CPU online if the hardware supported

both, the acpi-cpufreq and intel_pstate modules. This update ensures that
the acpi-cpufreq module is not loaded in the intel_pstate module is
loaded. (BZ#1134716)

• Due to a bug in the time accounting of the kernel scheduler, a divide

error could occur when hot adding a CPU. To fix this problem, the kernel
scheduler time accounting has been reworked. (BZ#1134717)

• The kernel did not handle exceptions caused by an invalid floating point

control (FPC) register, resulting in a kernel oops. This problem has been
fixed by placing the label to handle these exceptions to the correct place
in the code. (BZ#1138733)

• A previous change to the kernel for the PowerPC architecture changed

implementation of the compat_sys_sendfile() function. Consequently, the
64-bit sendfile() system call stopped working for files larger than 2 GB
on PowerPC. This update restores previous behavior of sendfile() on
PowerPC, and it again process files bigger than 2 GB as expected.
(BZ#1139126)

• Previously, the kernel scheduler could schedule a CPU topology update

even though the topology did not change. This could negatively affect the
CPU load balancing, cause degradation of the system performance, and
eventually result in a kernel oops. This problem has been fixed by
skipping the CPU topology update if the topology has not actually changed.
(BZ#1140300)

• Previously, recovery of a double-degraded RAID6 array could, under

certain circumstances, result in data corruption. This could happen
because the md driver was using an optimization that is safe to use only
for single-degraded arrays. This update ensures that this optimization is
skipped during the recovery of double-degraded RAID6 arrays. (BZ#1143850)

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.

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/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 Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.3 x86_64

Fixes

• BZ - 1113409 - CVE-2014-4653 Kernel: ALSA: control: do not access controls outside of protected regions
• BZ - 1122982 - CVE-2014-5077 Kernel: net: SCTP: fix a NULL pointer dereference during INIT collisions
• BZ - 1144825 - CVE-2014-3646 kernel: kvm: vmx: invvpid vm exit not handled
• BZ - 1144835 - CVE-2014-3645 kernel: kvm: vmx: invept vm exit not handled
• BZ - 1144878 - CVE-2014-3611 kernel: kvm: PIT timer race condition

CVEs

• CVE-2014-5077
• CVE-2014-4653
• CVE-2014-3611
• CVE-2014-3646
• CVE-2014-3645

References