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ESB-2016.0388 - [RedHat] kernel and kernel-rt: Multiple vulnerabilities

Date: 17 February 2016
References: ESB-2015.1942  ESB-2015.2806.2  ESB-2015.3143  

Click here for printable version
Click here for PGP verifiable version
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===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2016.0388
                    Important: kernel security updates
                             17 February 2016

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           kernel
                   kernel-rt
Publisher:         Red Hat
Operating System:  Red Hat Enterprise Linux Server 7
                   Red Hat Enterprise Linux WS/Desktop 7
                   Red Hat Enterprise Linux Server 6
Impact/Access:     Root Compromise   -- Existing Account
                   Denial of Service -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2015-7872 CVE-2015-5157 

Reference:         ESB-2015.3143
                   ESB-2015.2806.2
                   ESB-2015.1942

Original Bulletin: 
   https://rhn.redhat.com/errata/RHSA-2016-0185.html
   https://rhn.redhat.com/errata/RHSA-2016-0212.html
   https://rhn.redhat.com/errata/RHSA-2016-0224.html

Comment: This bulletin contains three (3) Red Hat security advisories.

- --------------------------BEGIN INCLUDED TEXT--------------------

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

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

Synopsis:          Important: kernel security and bug fix update
Advisory ID:       RHSA-2016:0185-01
Product:           Red Hat Enterprise Linux
Advisory URL:      https://rhn.redhat.com/errata/RHSA-2016-0185.html
Issue date:        2016-02-16
CVE Names:         CVE-2015-5157 CVE-2015-7872 
=====================================================================

1. Summary:

Updated kernel packages that fix two security issues and several 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Client (v. 7) - noarch, x86_64
Red Hat Enterprise Linux Client Optional (v. 7) - x86_64
Red Hat Enterprise Linux ComputeNode (v. 7) - noarch, x86_64
Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64
Red Hat Enterprise Linux Server (v. 7) - noarch, ppc64, ppc64le, s390x, x86_64
Red Hat Enterprise Linux Server Optional (v. 7) - ppc64, ppc64le, x86_64
Red Hat Enterprise Linux Workstation (v. 7) - noarch, x86_64
Red Hat Enterprise Linux Workstation Optional (v. 7) - x86_64

3. Description:

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

* It was found that the Linux kernel's keys subsystem did not correctly
garbage collect uninstantiated keyrings. A local attacker could use this
flaw to crash the system or, potentially, escalate their privileges on the
system. (CVE-2015-7872, Important)

* A flaw was found in the way the Linux kernel handled IRET faults during
the processing of NMIs. An unprivileged, local user could use this flaw to
crash the system or, potentially (although highly unlikely), escalate their
privileges on the system. (CVE-2015-5157, Moderate)

This update also fixes the following bugs:

* Previously, processing packets with a lot of different IPv6 source
addresses caused the kernel to return warnings concerning soft-lockups due
to high lock contention and latency increase. With this update, lock
contention is reduced by backing off concurrent waiting threads on the
lock. As a result, the kernel no longer issues warnings in the described
scenario. (BZ#1285370)

* Prior to this update, block device readahead was artificially limited.
As a consequence, the read performance was poor, especially on RAID
devices. Now, per-device readahead limits are used for each device instead
of a global limit. As a result, read performance has improved, especially
on RAID devices. (BZ#1287550)

* After injecting an EEH error, the host was previously not recovering and
observing I/O hangs in HTX tool logs. This update makes sure that when one
or both of EEH_STATE_MMIO_ACTIVE and EEH_STATE_MMIO_ENABLED flags is marked
in the PE state, the PE's IO path is regarded as enabled as well. As a
result, the host no longer hangs and recovers as expected. (BZ#1289101)

* The genwqe device driver was previously using the GFP_ATOMIC flag for
allocating consecutive memory pages from the kernel's atomic memory pool,
even in non-atomic situations. This could lead to allocation failures
during memory pressure. With this update, the genwqe driver's memory
allocations use the GFP_KERNEL flag, and the driver can allocate memory
even during memory pressure situations. (BZ#1289450)

* The nx842 co-processor for IBM Power Systems could in some circumstances
provide invalid data due to a data corruption bug during uncompression.
With this update, all compression and uncompression calls to the nx842
co-processor contain a cyclic redundancy check (CRC) flag, which forces all
compression and uncompression operations to check data integrity and
prevents the co-processor from providing corrupted data. (BZ#1289451)

* A failed "updatepp" operation on the little-endian variant of IBM Power
Systems could previously cause a wrong hash value to be used for the next
hash insert operation in the page table. This could result in a missing
hash pte update or invalidate operation, potentially causing memory
corruption. With this update, the hash value is always recalculated after a
failed "updatepp" operation, avoiding memory corruption. (BZ#1289452)

* Large Receive Offload (LRO) flag disabling was not being propagated
downwards from above devices in vlan and bond hierarchy, breaking the flow
of traffic. This problem has been fixed and LRO flags now propagate
correctly. (BZ#1292072)

* Due to rounding errors in the CPU frequency of the intel_pstate driver,
the CPU frequency never reached the value requested by the user. A kernel
patch has been applied to fix these rounding errors. (BZ#1296276)

* When running several containers (up to 100), reports of hung tasks were
previously reported. This update fixes the AB-BA deadlock in the
dm_destroy() function, and the hung reports no longer occur. (BZ#1296566)

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.

4. 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

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

1259577 - CVE-2015-5157 kernel: x86-64: IRET faults during NMIs processing
1272371 - CVE-2015-7872 kernel: Keyrings crash triggerable by unprivileged user

6. Package List:

Red Hat Enterprise Linux Client (v. 7):

Source:
kernel-3.10.0-327.10.1.el7.src.rpm

noarch:
kernel-abi-whitelists-3.10.0-327.10.1.el7.noarch.rpm
kernel-doc-3.10.0-327.10.1.el7.noarch.rpm

x86_64:
kernel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-headers-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-3.10.0-327.10.1.el7.x86_64.rpm
perf-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm

Red Hat Enterprise Linux Client Optional (v. 7):

x86_64:
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm

Red Hat Enterprise Linux ComputeNode (v. 7):

Source:
kernel-3.10.0-327.10.1.el7.src.rpm

noarch:
kernel-abi-whitelists-3.10.0-327.10.1.el7.noarch.rpm
kernel-doc-3.10.0-327.10.1.el7.noarch.rpm

x86_64:
kernel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-headers-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-3.10.0-327.10.1.el7.x86_64.rpm
perf-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm

Red Hat Enterprise Linux ComputeNode Optional (v. 7):

x86_64:
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm

Red Hat Enterprise Linux Server (v. 7):

Source:
kernel-3.10.0-327.10.1.el7.src.rpm

noarch:
kernel-abi-whitelists-3.10.0-327.10.1.el7.noarch.rpm
kernel-doc-3.10.0-327.10.1.el7.noarch.rpm

ppc64:
kernel-3.10.0-327.10.1.el7.ppc64.rpm
kernel-bootwrapper-3.10.0-327.10.1.el7.ppc64.rpm
kernel-debug-3.10.0-327.10.1.el7.ppc64.rpm
kernel-debug-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
kernel-debug-devel-3.10.0-327.10.1.el7.ppc64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
kernel-debuginfo-common-ppc64-3.10.0-327.10.1.el7.ppc64.rpm
kernel-devel-3.10.0-327.10.1.el7.ppc64.rpm
kernel-headers-3.10.0-327.10.1.el7.ppc64.rpm
kernel-tools-3.10.0-327.10.1.el7.ppc64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
kernel-tools-libs-3.10.0-327.10.1.el7.ppc64.rpm
perf-3.10.0-327.10.1.el7.ppc64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
python-perf-3.10.0-327.10.1.el7.ppc64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm

ppc64le:
kernel-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-bootwrapper-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-debug-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-debug-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-debuginfo-common-ppc64le-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-devel-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-headers-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-tools-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-tools-libs-3.10.0-327.10.1.el7.ppc64le.rpm
perf-3.10.0-327.10.1.el7.ppc64le.rpm
perf-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
python-perf-3.10.0-327.10.1.el7.ppc64le.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm

s390x:
kernel-3.10.0-327.10.1.el7.s390x.rpm
kernel-debug-3.10.0-327.10.1.el7.s390x.rpm
kernel-debug-debuginfo-3.10.0-327.10.1.el7.s390x.rpm
kernel-debug-devel-3.10.0-327.10.1.el7.s390x.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.s390x.rpm
kernel-debuginfo-common-s390x-3.10.0-327.10.1.el7.s390x.rpm
kernel-devel-3.10.0-327.10.1.el7.s390x.rpm
kernel-headers-3.10.0-327.10.1.el7.s390x.rpm
kernel-kdump-3.10.0-327.10.1.el7.s390x.rpm
kernel-kdump-debuginfo-3.10.0-327.10.1.el7.s390x.rpm
kernel-kdump-devel-3.10.0-327.10.1.el7.s390x.rpm
perf-3.10.0-327.10.1.el7.s390x.rpm
perf-debuginfo-3.10.0-327.10.1.el7.s390x.rpm
python-perf-3.10.0-327.10.1.el7.s390x.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.s390x.rpm

x86_64:
kernel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-headers-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-3.10.0-327.10.1.el7.x86_64.rpm
perf-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm

Red Hat Enterprise Linux Server Optional (v. 7):

ppc64:
kernel-debug-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
kernel-debuginfo-common-ppc64-3.10.0-327.10.1.el7.ppc64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
kernel-tools-libs-devel-3.10.0-327.10.1.el7.ppc64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.ppc64.rpm

ppc64le:
kernel-debug-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-debug-devel-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-debuginfo-common-ppc64le-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
kernel-tools-libs-devel-3.10.0-327.10.1.el7.ppc64le.rpm
perf-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.ppc64le.rpm

x86_64:
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm

Red Hat Enterprise Linux Workstation (v. 7):

Source:
kernel-3.10.0-327.10.1.el7.src.rpm

noarch:
kernel-abi-whitelists-3.10.0-327.10.1.el7.noarch.rpm
kernel-doc-3.10.0-327.10.1.el7.noarch.rpm

x86_64:
kernel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debug-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-devel-3.10.0-327.10.1.el7.x86_64.rpm
kernel-headers-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-3.10.0-327.10.1.el7.x86_64.rpm
perf-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm

Red Hat Enterprise Linux Workstation Optional (v. 7):

x86_64:
kernel-debug-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-327.10.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-327.10.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-327.10.1.el7.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-2015-5157
https://access.redhat.com/security/cve/CVE-2015-7872
https://access.redhat.com/security/updates/classification/#important

8. Contact:

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

Copyright 2016 Red Hat, Inc.
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Hash: SHA1

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

Synopsis:          Important: kernel-rt security, bug fix, and enhancement update
Advisory ID:       RHSA-2016:0212-01
Product:           Red Hat Enterprise Linux
Advisory URL:      https://rhn.redhat.com/errata/RHSA-2016-0212.html
Issue date:        2016-02-16
CVE Names:         CVE-2015-5157 CVE-2015-7872 
=====================================================================

1. Summary:

Updated kernel-rt packages that fix two security issues, several bugs, and
add various enhancements 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Realtime (v. 7) - noarch, x86_64

3. Description:

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

* It was found that the Linux kernel's keys subsystem did not correctly
garbage collect uninstantiated keyrings. A local attacker could use this
flaw to crash the system or, potentially, escalate their privileges on the
system. (CVE-2015-7872, Important)

* A flaw was found in the way the Linux kernel handled IRET faults during
the processing of NMIs. An unprivileged, local user could use this flaw to
crash the system or, potentially (although highly unlikely), escalate their
privileges on the system. (CVE-2015-5157, Moderate)

The kernel-rt packages have been upgraded to version 3.10.0-327.10.1, which
provides a number of bug fixes and enhancements, including:

* [md] dm: fix AB-BA deadlock in __dm_destroy() 

* [md] revert "dm-mpath: fix stalls when handling invalid ioctl

* [cpufreq] intel_pstate: Fix limits->max_perf and limits->max_policy_pct
rounding errors

* [cpufreq] revert "intel_pstate: fix rounding error in max_freq_pct"

* [crypto] nx: 842 - Add CRC and validation support

* [of] return NUMA_NO_NODE from fallback of_node_to_nid()

(BZ#1282591)

This update also fixes the following bugs:

* Because the realtime kernel replaces most of the spinlocks with
rtmutexes, the locking scheme used in both NAPI polling and busy polling
could become out of synchronization with the State Machine they protected.
This could cause system performance degradation or even a livelock
situation when a machine with faster NICs (10g or 40g) was subject to a
heavy pressure receiving network packets. The locking schemes on NAPI
polling and busy polling routines have been hardened to enforce the State
machine sanity to help ensure the system continues to function properly
under pressure. (BZ#1293230)

* A possible livelock in the NAPI polling and busy polling routines could
lead the system to a livelock on threads running at high, realtime,
priorities. The threads running at priorities lower than the ones of the
threads involved in the livelock were prevented from running on the CPUs
affected by the livelock. Among those lower priority threads are the rcuc/
threads. With this update, right before (4 jiffies) a RCU stall is
detected, the rcuc/ threads on the CPUs facing the livelock have their
priorities boosted above the priority of the threads involved in the
livelock. The softirq code has also been updated to be more robust.
These modifications allow the rcuc/ threads to execute even under system
pressure, mitigating the RCU stalls. (BZ#1293229)

* Multiple CPUs trying to take an rq lock previously caused large latencies
on machines with many CPUs. On systems with more than 32 cores, this update
uses the "push" rather than "pull" approach and provides multiple changes
to the scheduling of rq locks. As a result, machines no longer suffer from
multiplied latencies on large CPU systems. (BZ#1282597)

* Previously, the SFC driver for 10 GB cards executed polling in NAPI mode,
using a locking mechanism similar to a "trylock". Consequently, when
running on a Realtime kernel, a livelock could occur. This update modifies
the locking mechanism so that once the lock is taken it is not released
until the operation is complete. (BZ#1282609)

All kernel-rt users are advised to upgrade to these updated packages, which
correct these issues and add these enhancements. The system must be
rebooted for this update to take effect.

4. 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

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

1259577 - CVE-2015-5157 kernel: x86-64: IRET faults during NMIs processing
1272371 - CVE-2015-7872 kernel: Keyrings crash triggerable by unprivileged user
1282591 - kernel-rt: update to the RHEL7.2.z batch 2 source tree
1293229 - RCU stalls message on realtime kernel
1293230 - rt: netpoll: live lock with NAPI polling and busy polling on realtime kernel

6. Package List:

Red Hat Enterprise Linux Realtime (v. 7):

Source:
kernel-rt-3.10.0-327.10.1.rt56.211.el7_2.src.rpm

noarch:
kernel-rt-doc-3.10.0-327.10.1.rt56.211.el7_2.noarch.rpm

x86_64:
kernel-rt-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-debug-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-debug-debuginfo-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-debug-devel-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-debuginfo-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-devel-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-trace-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-trace-debuginfo-3.10.0-327.10.1.rt56.211.el7_2.x86_64.rpm
kernel-rt-trace-devel-3.10.0-327.10.1.rt56.211.el7_2.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-2015-5157
https://access.redhat.com/security/cve/CVE-2015-7872
https://access.redhat.com/security/updates/classification/#important

8. Contact:

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

Copyright 2016 Red Hat, Inc.
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Hash: SHA1

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

Synopsis:          Important: kernel-rt security, bug fix, and enhancement update
Advisory ID:       RHSA-2016:0224-01
Product:           Red Hat Enterprise MRG for RHEL-6
Advisory URL:      https://rhn.redhat.com/errata/RHSA-2016-0224.html
Issue date:        2016-02-16
CVE Names:         CVE-2015-5157 CVE-2015-7872 
=====================================================================

1. Summary:

Updated kernel-rt packages that fix two security issues, several bugs, and
add various enhancements are now available for Red Hat Enterprise MRG 2.5.

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.

2. Relevant releases/architectures:

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

3. Description:

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

* It was found that the Linux kernel's keys subsystem did not correctly
garbage collect uninstantiated keyrings. A local attacker could use this
flaw to crash the system or, potentially, escalate their privileges on the
system. (CVE-2015-7872, Important)

* A flaw was found in the way the Linux kernel handled IRET faults during
the processing of NMIs. An unprivileged, local user could use this flaw to
crash the system or, potentially (although highly unlikely), escalate their
privileges on the system. (CVE-2015-5157, Moderate)

This update provides a build of the kernel-rt package for Red Hat
Enterprise MRG 2.5 that is layered on Red Hat Enterprise Linux 6, and
provides a number of bug fixes and enhancements, including:

* [md] dm: fix AB-BA deadlock in __dm_destroy() 

* [md] revert "dm-mpath: fix stalls when handling invalid ioctl

* [cpufreq] intel_pstate: Fix limits->max_perf and limits->max_policy_pct
rounding errors

* [cpufreq] revert "intel_pstate: fix rounding error in max_freq_pct"

* [crypto] nx: 842 - Add CRC and validation support

* [of] return NUMA_NO_NODE from fallback of_node_to_nid()

(BZ#1277670)

The HP Smart Array (hpsa) SCSI driver has been updated to the latest
version included in a Red Hat release. (BZ#1224096)

This update also fixes the following bugs:

* A heavy load of incoming packets on a fast networking driver (like the
i40e) will both stress the softirq mechanism on the realtime kernel (as
described in BZ#1293229) and exercise the possible livelock in the netpoll
NAPI/busy polling routines (as described in BZ#1293230). The fixes applied
to both BZ#1293229 and BZ#1293230 will address these issues by hardening
the locking mechanism for the netpoll NAPI/busy polling and by enhancing
the way softirqs are serviced. These fixes also create a failsafe to
avoiding RCU stalls on a heavily loaded system and allows the networking
driver to work as expected. (BZ#1200766)

* The nohz_full code in older versions of the MRG-Realtime kernels was
incomplete and known to be problematic due to the way the old
implementation interacted with the real time features in the kernel.
The nohz_full kernel code has been updated enabling this feature to
function as expected and allowing this feature to be enabled in the
realtime kernel. (BZ#1278511)

* Because the realtime kernel replaces most of the spinlocks with
rtmutexes, the locking scheme used in both NAPI polling and busy polling
could become out of synchronization with the State Machine they protected.
This could cause system performance degradation or even a livelock
situation when a machine with faster NICs (10g or 40g) was subject to a
heavy pressure receiving network packets. The locking schemes on NAPI
polling and busy polling routines were hardened to enforce the State
machine sanity to help ensure the system continues to function properly
under pressure. (BZ#1295884)

* A possible livelock in the NAPI polling and busy polling routines could
lead the system to a livelock on threads running at high, realtime,
priorities. The threads running at priorities lower than the ones of the
threads involved in the livelock would be prevented from running on the
CPUs affected by the livelock. Among those lower priority threads are the
rcuc/ threads. Right before (4 jiffies) a RCU stall is detected, the rcuc/
threads on the CPUs facing the livelock have their priorities boosted above
the priority of the threads involved in the livelock. The softirq code was
also updated to be more robust. These modifications allowed the rcuc/
threads to execute even under system pressure, mitigating the RCU stalls.
(BZ#1295885)

All kernel-rt users are advised to upgrade to these updated packages, which
correct these issues and add these enhancements. The system must be
rebooted for this update to take effect.

4. 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

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

1259577 - CVE-2015-5157 kernel: x86-64: IRET faults during NMIs processing
1272371 - CVE-2015-7872 kernel: Keyrings crash triggerable by unprivileged user
1277670 - update the MRG 2.5.x 3.10 kernel-rt sources
1278511 - nohz_full still not working even with nohz=on

6. Package List:

MRG Realtime for RHEL 6 Server v.2:

Source:
kernel-rt-3.10.0-327.rt56.171.el6rt.src.rpm

noarch:
kernel-rt-doc-3.10.0-327.rt56.171.el6rt.noarch.rpm
kernel-rt-firmware-3.10.0-327.rt56.171.el6rt.noarch.rpm

x86_64:
kernel-rt-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-debug-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-debug-debuginfo-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-debug-devel-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-debuginfo-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-devel-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-trace-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-trace-debuginfo-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-trace-devel-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-vanilla-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-vanilla-debuginfo-3.10.0-327.rt56.171.el6rt.x86_64.rpm
kernel-rt-vanilla-devel-3.10.0-327.rt56.171.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-2015-5157
https://access.redhat.com/security/cve/CVE-2015-7872
https://access.redhat.com/security/updates/classification/#important

8. Contact:

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

Copyright 2016 Red Hat, Inc.
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- --------------------------END INCLUDED TEXT--------------------

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