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Red Hat Enterprise Linux 6.6: RHSA-2016-1939-01 Important Bug Fix

red hat
Calendar Grey September 27, 2016
Scroller Redhat
The recent kernel patch for Red Hat Enterprise Linux effectively resolves serious vulnerabilities related to data exposure and critical flaws.
An update for kernel is now available for Red Hat Enterprise Linux 6.6 Extended Update Support

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 packages contain the Linux kernel, the core of any Linux operating system.
Security Fix(es):
* It was found that the RFC 5961 challenge ACK rate limiting as implemented in the Linux kernel's networking subsystem allowed an off-path attacker to leak certain information about a given connection by creating congestion on the global challenge ACK rate limit counter and then measuring the changes by probing packets. An off-path attacker could use this flaw to either terminate TCP connection and/or inject payload into non-secured TCP connection between two endpoints on the network. (CVE-2016-5696, Important)
Red Hat would like to thank Yue Cao (Cyber Security Group of the CS department of University of California in Riverside) for reporting this issue.
Bug Fix(es):
* Previously, the BUG_ON() signal appeared in the fs_clear_inode() function where the nfs_have_writebacks() function reported a positive value for nfs_inode->npages. As a consequence, a kernel panic occurred. The provided patch performs a serialization by holding the inode i_lock over the check of PagePrivate and locking the request, which fixes this bug. (BZ#1365163)

Topics%20covered

Topics Covered

security advisory bug fix Red Hat Enterprise Linux important kernel information disclosure network threat

References

https://access.redhat.com/security/cve/CVE-2016-5696 https://access.redhat.com/security/updates/classification/#important

Package List

Red Hat Enterprise Linux HPC Node EUS (v. 6.6):
Source: kernel-2.6.32-504.52.1.el6.src.rpm
noarch: kernel-abi-whitelists-2.6.32-504.52.1.el6.noarch.rpm kernel-doc-2.6.32-504.52.1.el6.noarch.rpm kernel-firmware-2.6.32-504.52.1.el6.noarch.rpm
x86_64: kernel-2.6.32-504.52.1.el6.x86_64.rpm kernel-debug-2.6.32-504.52.1.el6.x86_64.rpm kernel-debug-debuginfo-2.6.32-504.52.1.el6.i686.rpm kernel-debug-debuginfo-2.6.32-504.52.1.el6.x86_64.rpm kernel-debug-devel-2.6.32-504.52.1.el6.i686.rpm kernel-debug-devel-2.6.32-504.52.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.52.1.el6.i686.rpm kernel-debuginfo-2.6.32-504.52.1.el6.x86_64.rpm kernel-debuginfo-common-i686-2.6.32-504.52.1.el6.i686.rpm kernel-debuginfo-common-x86_64-2.6.32-504.52.1.el6.x86_64.rpm kernel-devel-2.6.32-504.52.1.el6.x86_64.rpm kernel-headers-2.6.32-504.52.1.el6.x86_64.rpm perf-2.6.32-504.52.1.el6.x86_64.rpm perf-debuginfo-2.6.32-504.52.1.el6.i686.rpm perf-debuginfo-2.6.32-504.52.1.el6.x86_64.rpm python-perf-debuginfo-2.6.32-504.52.1.el6.i686.rpm python-perf-debuginfo-2.6.32-504.52.1.el6.x86_64.rpm
Red Hat Enterprise Linux HPC Node Optional EUS (v. 6.6):
x86_64: kernel-debug-debuginfo-2.6.32-504.52.1.el6.x86_64.rpm kernel-debuginfo-2.6.32-504.52.1.el6.x86_64.rpm

Read the Full Advisory


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2016:1939-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2016:1939.html
Issue date: 2016-09-27

Topic

An update for kernel is now available for Red Hat Enterprise Linux 6.6Extended Update Support.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 bug fix Red Hat Enterprise Linux important kernel information disclosure network threat

Relevant Releases Architectures

Red Hat Enterprise Linux HPC Node EUS (v. 6.6) - noarch, x86_64

Red Hat Enterprise Linux HPC Node Optional EUS (v. 6.6) - x86_64

Red Hat Enterprise Linux Server EUS (v. 6.6) - i386, noarch, ppc64, s390x, x86_64

Red Hat Enterprise Linux Server Optional EUS (v. 6.6) - i386, ppc64, s390x, x86_64

Bugs Fixed

1354708 - CVE-2016-5696 kernel: challenge ACK counter information disclosure.

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