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Red Hat 7: RHSA-2016:1875-01 Critical: Kernel-RT Security Risks

red hat
Calendar Grey September 15, 2016
Scroller Redhat
A major patch for the kernel in Red Hat Enterprise Linux resolves several vulnerabilities, boosting overall system safety. Implement it urgently.
An update for kernel-rt is now available for Red Hat Enterprise Linux 7

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.
The kernel-rt packages have been upgraded to the kernel-3.10.0-327.36.1 source tree, which provides a number of bug fixes over the previous version. (BZ#1366538)
Security Fix(es):
* A security flaw was found in the Linux kernel in the mark_source_chains() function in "net/ipv4/netfilter/ip_tables.c". It is possible for a user-supplied "ipt_entry" structure to have a large "next_offset" field. This field is not bounds checked prior to writing to a counter value at the supplied offset. (CVE-2016-3134, Important)
* A flaw was discovered in processing setsockopt for 32 bit processes on 64 bit systems. This flaw will allow attackers to alter arbitrary kernel memory when unloading a kernel module. This action is usually restricted to root-privileged users but can also be leveraged if the kernel is compiled with CONFIG_USER_NS and CONFIG_NET_NS and the user is granted elevated privileges. (CVE-2016-4997, Important)
* 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)

References

https://access.redhat.com/security/cve/CVE-2016-3134 https://access.redhat.com/security/cve/CVE-2016-4997 https://access.redhat.com/security/cve/CVE-2016-4998 https://access.redhat.com/security/updates/classification/#important

Package List

Red Hat Enterprise Linux for Real Time for NFV (v. 7):
Source: kernel-rt-3.10.0-327.36.1.rt56.237.el7.src.rpm
noarch: kernel-rt-doc-3.10.0-327.36.1.rt56.237.el7.noarch.rpm
x86_64: kernel-rt-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-debug-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-debug-debuginfo-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-debug-devel-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-debug-kvm-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-debug-kvm-debuginfo-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-debuginfo-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-debuginfo-common-x86_64-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-devel-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-kvm-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-kvm-debuginfo-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-trace-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-trace-debuginfo-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-trace-devel-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-trace-kvm-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm kernel-rt-trace-kvm-debuginfo-3.10.0-327.36.1.rt56.237.el7.x86_64.rpm
Red Hat Enterprise Linux Realtime (v. 7):
Source: kernel-rt-3.10.0-327.36.1.rt56.237.el7.src.rpm
noarch:

Read the Full Advisory


Severity
critical
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2016:1875-01
Product: Red Hat Enterprise Linux
Issue date: 2016-09-14

Topic

An update for kernel-rt is now available for Red Hat Enterprise Linux 7.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.

Relevant Releases Architectures

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

Red Hat Enterprise Linux for Real Time for NFV (v. 7) - noarch, x86_64

Bugs Fixed

1317383 - CVE-2016-3134 kernel: netfilter: missing bounds check in ipt_entry structure

1349722 - CVE-2016-4997 kernel: compat IPT_SO_SET_REPLACE setsockopt

1349886 - CVE-2016-4998 kernel: out of bounds reads when processing IPT_SO_SET_REPLACE setsockopt

1366538 - kernel-rt: update to the RHEL7.2.z batch#7 source tree

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