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Red Hat Enterprise MRG 2.5: RHSA-2016-2107-01 Critical Privilege Escalation

red hat
Calendar Grey October 26, 2016
Scroller Redhat
Important kernel-rt enhancement for Red Hat Enterprise MRG 2.5 resolves security vulnerabilities including privilege elevation and stack overflow concerns.
An update for kernel-rt is now available for Red Hat Enterprise MRG 2.5

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.

Summary

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.
Security Fix(es):
* A race condition was found in the way the Linux kernel's memory subsystem handled the copy-on-write (COW) breakage of private read-only memory mappings. An unprivileged, local user could use this flaw to gain write access to otherwise read-only memory mappings and thus increase their privileges on the system. (CVE-2016-5195, Important)
* Linux kernel built with the 802.1Q/802.1ad VLAN(CONFIG_VLAN_8021Q) OR Virtual eXtensible Local Area Network(CONFIG_VXLAN) with Transparent Ethernet Bridging(TEB) GRO support, is vulnerable to a stack overflow issue. It could occur while receiving large packets via GRO path; As an unlimited recursion could unfold in both VLAN and TEB modules, leading to a stack corruption in the kernel. (CVE-2016-7039, Important)
Red Hat would like to thank Phil Oester for reporting CVE-2016-5195.

Topics%20covered

Topics Covered

security advisory kernel update privilege escalation Red Hat Enterprise stack overflow

References

https://access.redhat.com/security/cve/CVE-2016-5195 https://access.redhat.com/security/cve/CVE-2016-7039 https://access.redhat.com/security/updates/classification#important https://access.redhat.com/security/vulnerabilities/DirtyCow

Package List

MRG Realtime for RHEL 6 Server v.2:
Source: kernel-rt-3.10.0-327.rt56.198.el6rt.src.rpm
noarch: kernel-rt-doc-3.10.0-327.rt56.198.el6rt.noarch.rpm kernel-rt-firmware-3.10.0-327.rt56.198.el6rt.noarch.rpm
x86_64: kernel-rt-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-debug-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-debug-debuginfo-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-debug-devel-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-debuginfo-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-debuginfo-common-x86_64-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-devel-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-trace-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-trace-debuginfo-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-trace-devel-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-vanilla-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-vanilla-debuginfo-3.10.0-327.rt56.198.el6rt.x86_64.rpm kernel-rt-vanilla-devel-3.10.0-327.rt56.198.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


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2016:2107-01
Product: Red Hat Enterprise MRG for RHEL-6
Advisory URL: https://access.redhat.com/errata/RHSA-2016:2107.html
Issue date: 2016-10-26

Topic

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 impactof Important. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available for each vulnerabilityfrom the CVE link(s) in the References section.

Topics%20covered

Topics Covered

security advisory kernel update privilege escalation Red Hat Enterprise stack overflow

Relevant Releases Architectures

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

Bugs Fixed

1375944 - CVE-2016-7039 kernel: remotely triggerable unbounded recursion in the vlan gro code leading to a kernel crash

1384344 - CVE-2016-5195 kernel: mm: privilege escalation via MAP_PRIVATE COW breakage

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