RHEL 6 : kernel-rt (RHSA-2018:0181)

High Nessus Plugin ID 106525

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 MRG 2.

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 flaw was found in the Linux kernel's key management system where it was possible for an attacker to escalate privileges or crash the machine. If a user key gets negatively instantiated, an error code is cached in the payload area. A negatively instantiated key may be then be positively instantiated by updating it with valid data. However, the ->update key type method must be aware that the error code may be there. (CVE-2015-8539, Important)

* It was found that fanout_add() in 'net/packet/af_packet.c' in the Linux kernel, before version 4.13.6, allows local users to gain privileges via crafted system calls that trigger mishandling of packet_fanout data structures, because of a race condition (involving fanout_add and packet_do_bind) that leads to a use-after-free bug.
(CVE-2017-15649, Important)

* A vulnerability was found in the Linux kernel where the keyctl_set_reqkey_keyring() function leaks the thread keyring. This allows an unprivileged local user to exhaust kernel memory and thus cause a DoS. (CVE-2017-7472, Moderate)

Red Hat would like to thank Dmitry Vyukov of Google engineering for reporting CVE-2015-8539.

Bug Fix(es) :

* The mlx5 driver has a number of configuration options, including the selective support for network protocols, such as InfiniBand and Ethernet. Due to a regression in the configuration of the MRG-RT kernel, the Ethernet mode of the driver was turned off. The regression has been resolved by enabling the mlx5 Ethernet mode, making the Ethernet protocol to work again. (BZ#1422778)

* The migrate_disable/enable() kernel operations are used to pin a thread to a CPU temporarily. This method is a kernel-rt specific. To keep RHEL-RT's kernel up-to-date with the latest real-time kernel, the migrate_disable/ enable routine was updated to the version present on kernel v4.9-rt. However, this version showed to be problematic. The changes in the migrate_disable/enabled have been thus reverted to a stable version, avoiding the kernel BUG. (BZ#1507831)

* The kernel-rt packages have been upgraded to version 3.10.0-693.15.1.rt56.601, which provides a number of security and bug fixes over the previous version. (BZ#1519504)

Solution

Update the affected packages.

See Also

https://access.redhat.com/errata/RHSA-2018:0181

https://access.redhat.com/security/cve/cve-2015-8539

https://access.redhat.com/security/cve/cve-2017-7472

https://access.redhat.com/security/cve/cve-2017-15649

Plugin Details

Severity: High

ID: 106525

File Name: redhat-RHSA-2018-0181.nasl

Version: 3.3

Type: local

Agent: unix

Published: 2018/01/31

Modified: 2018/11/10

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 7.2

Temporal Score: 5.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: CVSS2#E:POC/RL:OF/RC:C

CVSS v3.0

Base Score: 7.8

Temporal Score: 7

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

Temporal Vector: CVSS:3.0/E:P/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-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-firmware, 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-vanilla, p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla-devel, cpe:/o:redhat:enterprise_linux:6

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: 2018/01/25

Reference Information

CVE: CVE-2015-8539, CVE-2017-15649, CVE-2017-7472

RHSA: 2018:0181