[CentOS] [Security Advisory] RHSA-2017:0036 Important: kernel security and bug fix update

Thu Jan 12 18:05:39 UTC 2017
Phelps, Matthew <mphelps at cfa.harvard.edu>

Any word on this update for CentOS 6? This one seems pretty bad if it's a
remote exploit.

Matt Phelps
System Administrator, Computation Facility
Harvard - Smithsonian Center for Astrophysics
mphelps at cfa.harvard.edu, http://www.cfa.harvard.edu

---------- Forwarded message ----------
From: Red Hat Errata Notifications <errata at redhat.com>
Date: Tue, Jan 10, 2017 at 5:19 PM
Subject: [Security Advisory] RHSA-2017:0036 Important: kernel security and
bug fix update
To: mphelps at cfa.harvard.edu

The following Red Hat Security Advisory has been published which may affect
subscriptions which you have purchased.

RHSA-2017:0036 Important: kernel security and bug fix update


An update for kernel is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact
of Important. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available for each vulnerability
from the CVE link(s) in the References section.

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

Security Fix(es):

* A use-after-free vulnerability was found in the kernels socket recvmmsg
subsystem. This may allow remote attackers to corrupt memory and may allow
execution of arbitrary code. This corruption takes place during the error
handling routines within __sys_recvmmsg() function. (CVE-2016-7117,

* An out-of-bounds heap memory access leading to a Denial of Service, heap
disclosure, or further impact was found in setsockopt(). The function call
is normally restricted to root, however some processes with cap_sys_admin
may also be able to trigger this flaw in privileged container environments.
(CVE-2016-4998, Moderate)

* A use-after-free vulnerability was found in tcp_xmit_retransmit_queue and
other tcp_* functions. This condition could allow an attacker to send an
incorrect selective acknowledgment to existing connections, possibly
resetting a connection. (CVE-2016-6828, Moderate)

Bug Fix(es):

* When parallel NFS returned a file layout, a kernel crash sometimes
occurred. This update removes the call to the BUG_ON() function from a code
path of a client that returns the file layout. As a result, the kernel no
longer crashes in the described situation. (BZ#1385480)

* When a guest virtual machine (VM) on Microsoft Hyper-V was set to crash
on a Nonmaskable Interrupt (NMI) that was injected from the host, this VM
became unresponsive and did not create the vmcore dump file. This update
applies a set of patches to the Virtual Machine Bus kernel driver
(hv_vmbus) that fix this bug. As a result, the VM now first creates and
saves the vmcore dump file and then reboots. (BZ#1385482)

* From Red Hat Enterprise Linux 6.6 to 6.8, the IPv6 routing cache
occasionally showed incorrect values. This update fixes the DST_NOCOUNT
mechanism, and the IPv6 routing cache now shows correct values. (BZ#1391974)

* When using the ixgbe driver and the software Fibre Channel over Ethernet
(FCoE) stack, suboptimal performance in some cases occurred on systems with
a large number of CPUs. This update fixes the fc_exch_alloc() function to
try all the available exchange managers in the list for an available
exchange ID. This change avoids failing allocations, which previously led
to the host busy status. (BZ#1392818)

* When the vmwgfx kernel module loads, it overrides the boot resolution
automatically. Consequently, users were not able to change the resolution
by manual setting of the kernel's 'vga=' parameter in the
/boot/grub/grub.conf file. This update adds the 'nomodeset' parameter,
which can be set in the /boot/grub/grub.conf file. The 'nomodeset'
parameter allows the users to prevent the vmwgfx driver from loading. As a
result, the setting of the 'vga=' parameter works as expected, in case that
vmwgfx does not load. (BZ#1392875)

* When Red Hat Enterprise Linux 6.8 was booted on SMBIOS 3.0 based systems,
Desktop Management Interface (DMI) information, which is referenced by
several applications, such as NEC server's memory RAS utility, was missing
entries in the sysfs virtual file system. This update fixes the underlying
source code, and sysfs now shows the DMI information as expected.

* Previously, bonding mode active backup and the propagation of the media
access control (MAC) address to a VLAN interface did not work in Red Hat
Enterprise Linux 6.8, when the fail_over_mac bonding parameter was set to
fail_over_mac=active. With this update, the underlying source code has been
fixed so that the VLANs continue inheriting the MAC address of the active
physical interface until the VLAN MAC address is explicitly set to any
value. As a result, IPv6 EUI64 addresses for the VLAN can reflect any
changes to the MAC address of the physical interface, and Duplicate Address
Detection (DAD) behaves as expected. (BZ#1396479)

Full details and references:


CVE Names:

CVE-2016-4998 CVE-2016-6828 CVE-2016-7117

Revision History:

Issue Date: 2017-01-10
Updated:    2017-01-10

Manage Errata Notifications

You are receiving this email because you have elected to receive errata
from Red Hat. This message is being sent to:
    Red Hat login:         mphelps2013
    Email address on file: <mphelps at cfa.harvard.edu>

Update your preferences at https://www.redhat.com/wapps/


The Red Hat security contact is secalert at redhat.com.  More contact
details at https://access.redhat.com/security/team/contact/

This is an automated message. Please do not reply. If you have further
questions or concerns,
please contact Red Hat Technical Support https://access.redhat.com/
or open a support case via the Red Hat Customer Portal

Copyright 2017 Red Hat, Inc.