RHEL 7 : kernel-rt (RHSA-2017:0931)

high Nessus Plugin ID 99344
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

The remote Red Hat host is missing one or more security updates.

Description

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 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.

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 flaw was found in the N_HLDC Linux kernel driver when accessing n_hdlc.tbuf list that can lead to double free. A local, unprivileged user able to set the HDLC line discipline on the tty device could use this flaw to increase their privileges on the system.
(CVE-2017-2636, Important)

* A flaw was found in the Linux kernel key management subsystem in which a local attacker could crash the kernel or corrupt the stack and additional memory (denial of service) by supplying a specially crafted RSA key. This flaw panics the machine during the verification of the RSA key. (CVE-2016-8650, Moderate)

* A flaw was found in the Linux kernel's implementation of setsockopt for the SO_{SND|RCV}BUFFORCE setsockopt() system call. Users with non-namespace CAP_NET_ADMIN are able to trigger this call and create a situation in which the sockets sendbuff data size could be negative.
This could adversely affect memory allocations and create situations where the system could crash or cause memory corruption.
(CVE-2016-9793, Moderate)

* A flaw was found in the Linux kernel's handling of clearing SELinux attributes on /proc/pid/attr files. An empty (null) write to this file can crash the system by causing the system to attempt to access unmapped kernel memory. (CVE-2017-2618, Moderate)

Red Hat would like to thank Alexander Popov for reporting CVE-2017-2636 and Ralf Spenneberg for reporting CVE-2016-8650. The CVE-2017-2618 issue was discovered by Paul Moore (Red Hat Engineering).

Bug Fix(es) :

* Previously, a cgroups data structure was sometimes corrupted due to a race condition in the kernel-rt cgroups code. Consequently, several system tasks were blocked, and the operating system became unresponsive. This update adds a lock that prevents the race condition. As a result, the cgroups data structure no longer gets corrupted and the operating system no longer hangs under the described circumstances. (BZ#1420784)

* The kernel-rt packages have been upgraded to the 3.10.0-514.16.1 source tree, which provides a number of bug fixes over the previous version. (BZ# 1430749)

Solution

Update the affected packages.

See Also

https://access.redhat.com/errata/RHSA-2017:0931

https://access.redhat.com/security/cve/cve-2016-8650

https://access.redhat.com/security/cve/cve-2016-9793

https://access.redhat.com/security/cve/cve-2017-2618

https://access.redhat.com/security/cve/cve-2017-2636

Plugin Details

Severity: High

ID: 99344

File Name: redhat-RHSA-2017-0931.nasl

Version: 3.13

Type: local

Agent: unix

Published: 4/13/2017

Updated: 10/24/2019

Dependencies: ssh_get_info.nasl, linux_alt_patch_detect.nasl

Risk Information

VPR

Risk Factor: High

Score: 8.4

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6

Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: E:F/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.2

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:F/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:kernel-rt, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-kvm-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-debuginfo-common-x86_64, p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-doc, p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-kvm-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-devel, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-kvm, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-kvm-debuginfo, cpe:/o:redhat:enterprise_linux:7

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 4/12/2017

Vulnerability Publication Date: 11/28/2016

Exploitable With

Core Impact

Reference Information

CVE: CVE-2016-8650, CVE-2016-9793, CVE-2017-2618, CVE-2017-2636

RHSA: 2017:0931