-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

=====================================================================
                   Red Hat Security Advisory

Synopsis:          Important: kernel-rt security and bug fix update
Advisory ID:       RHSA-2017:0113-01
Product:           Red Hat Enterprise MRG for RHEL-6
Advisory URL:      https://rhn.redhat.com/errata/RHSA-2017-0113.html
Issue date:        2017-01-17
CVE Names:         CVE-2016-6828 CVE-2016-7117 CVE-2016-9555 
=====================================================================

1. Summary:

An update for kernel-rt is now available for Red Hat Enterprise MRG 2.5.

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.

2. Relevant releases/architectures:

MRG Realtime for RHEL 6 Server v.2 - noarch, x86_64

3. Description:

The kernel-rt packages provide the Real Time Linux Kernel, which enables
fine-tuning for systems with extremely high determinism requirements.

The kernel-rt packages have been upgraded to version 3.10.0-514, which
provides a number of security and bug fixes over the previous version.
(BZ#1400193)

Security Fix(es):

* A use-after-free vulnerability was found in the kernel's 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,
Important)

* 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)

* A flaw was found in the Linux kernel's implementation of sctp protocol in
which a remote attacker can trigger an out of bounds read with an offset of
up to 64kB. This may panic the machine with a page-fault. (CVE-2016-9555,
Moderate)

Bug Fix(es):

* Previously, console warnings from the real-time kernel were generated
when a sleeping lock was acquired in atomic context. With this update, the
code has been modified to not acquire a sleeping lock in this context. As a
result, the console warnings are no longer generated. (BZ#1378982)

* Previously, the device mapper (DM) subsystem was not notified that the
real-time kernel changes the way preemption works with spinlocks. This
caused a kernel panic when the dm-multipath kernel module was loaded
because the interrupt request (IRQ) check was invalid on the real-time
kernel. This check has been corrected enabling the system to boot correctly
with the dm-multipath module enabled. (BZ#1400305)

* Previously, the kernel could sometimes panic due to a possible division
by zero in the scheduler. This bug has been fixed by defining a new
div64_ul() division function and correcting the affected calculation in the
proc_sched_show_task() function. (BZ#1400975)

* Unlike the standard Linux kernel, the real-time kernel does not disable
interrupts inside the Interrupt Service Routines driver. Because of this
difference, a New API (NAPI) function for turning interrupt requests (IRQ)
off was actually being called with IRQs enabled. Consequently, the NAPI
poll list was being corrupted, causing improper networking card operation
and potential kernel hangs. With this update, the NAPI function has been
corrected to force modifications of the poll list to be protected allowing
proper operation of the networking card drivers. (BZ#1401779)

Enhancement(s):

* With this update, the CONFIG_SLUB_DEBUG and CONFIG_SLABINFO kernel
configuration options are enabled in the real-time kernel. These options
turn on SLUB allocator debugging and slab information tracking, which are
helpful when investigating kernel memory allocation problems. (BZ#1357997)

4. Solution:

For details on how to apply this update, which includes the changes
described in this advisory, refer to:

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

The system must be rebooted for this update to take effect.

5. Bugs fixed (https://bugzilla.redhat.com/):

1346444 - [mrg] update kernel-rt sources
1357997 - Enable CONFIG_SLUB_DEBUG and CONFIG_SLABINFO
1367091 - CVE-2016-6828 kernel: Use after free in tcp_xmit_retransmit_queue
1378982 - BUG: using smp_processor_id() in preemptible
1382268 - CVE-2016-7117 kernel: Use-after-free in the recvmmsg exit path
1397930 - CVE-2016-9555 kernel: Slab out-of-bounds access in sctp_sf_ootb()
1400193 - update the MRG 2.5.z 3.10 kernel-rt sources
1400305 - RT kernel panics with dm-multipath enabled [mrg]
1401779 - NIC hangs due to corrupt napi lists

6. Package List:

MRG Realtime for RHEL 6 Server v.2:

Source:
kernel-rt-3.10.0-514.rt56.210.el6rt.src.rpm

noarch:
kernel-rt-doc-3.10.0-514.rt56.210.el6rt.noarch.rpm
kernel-rt-firmware-3.10.0-514.rt56.210.el6rt.noarch.rpm

x86_64:
kernel-rt-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-debug-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-debug-debuginfo-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-debug-devel-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-debuginfo-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-devel-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-trace-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-trace-debuginfo-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-trace-devel-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-vanilla-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-vanilla-debuginfo-3.10.0-514.rt56.210.el6rt.x86_64.rpm
kernel-rt-vanilla-devel-3.10.0-514.rt56.210.el6rt.x86_64.rpm

These packages are GPG signed by Red Hat for security.  Our key and
details on how to verify the signature are available from
https://access.redhat.com/security/team/key/

7. References:

https://access.redhat.com/security/cve/CVE-2016-6828
https://access.redhat.com/security/cve/CVE-2016-7117
https://access.redhat.com/security/cve/CVE-2016-9555
https://access.redhat.com/security/updates/classification/#important
https://access.redhat.com/security/vulnerabilities/2706661

8. Contact:

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

Copyright 2017 Red Hat, Inc.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iD8DBQFYfm7SXlSAg2UNWIIRAkrWAJoDaDrfp14M7PGi51A2nOTpHgDPiQCeIUkr
BgAeqcoqsN8UWczQYDnNjIw=
=77qN
-----END PGP SIGNATURE-----


--
RHSA-announce mailing list
RHSA-announce@redhat.com
https://www.redhat.com/mailman/listinfo/rhsa-announce