RHEL 7 : kernel-rt (RHSA-2017:0387)

high Nessus Plugin ID 97510
New! Vulnerability Priority Rating (VPR)

Tenable calculates a dynamic VPR for every vulnerability. VPR combines vulnerability information with threat intelligence and machine learning algorithms to predict which vulnerabilities are most likely to be exploited in attacks. Read more about what VPR is and how it is different from CVSS.

VPR Score: 8.9

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) :

* Linux kernel built with the Kernel-based Virtual Machine (CONFIG_KVM) support is vulnerable to a NULL pointer dereference flaw.
It could occur on x86 platform, when emulating an undefined instruction. An attacker could use this flaw to crash the host kernel resulting in DoS. (CVE-2016-8630, Important)

* A race condition issue leading to a use-after-free flaw was found in the way the raw packet sockets implementation in the Linux kernel networking subsystem handled synchronization while creating the TPACKET_V3 ring buffer. A local user able to open a raw packet socket (requires the CAP_NET_RAW capability) could use this flaw to elevate their privileges on the system. (CVE-2016-8655, Important)

* A flaw was discovered in the Linux kernel's implementation of VFIO.
An attacker issuing an ioctl can create a situation where memory is corrupted and modify memory outside of the expected area. This may overwrite kernel memory and subvert kernel execution. (CVE-2016-9083, Important)

* The use of a kzalloc with an integer multiplication allowed an integer overflow condition to be reached in vfio_pci_intrs.c. This combined with CVE-2016-9083 may allow an attacker to craft an attack and use unallocated memory, potentially crashing the machine.
(CVE-2016-9084, Moderate)

Red Hat would like to thank Philip Pettersson for reporting CVE-2016-8655.

Bug Fix(es) :

* Previously, the asynchronous page fault woke code references spinlocks, which were actually sleeping locks in the RT kernel.
Because of this, when the code was executed from the exception context, a bug warning appeared on the console. With this update, the regular wait queue and spinlock code in this area has been modified to use simple-wait-queue and raw-spinlocks. This code change enables the asynchronous page fault code to run in a non-preemptable state without bug warnings. (BZ#1418035)

Solution

Update the affected packages.

See Also

https://access.redhat.com/errata/RHSA-2017:0387

https://access.redhat.com/security/cve/cve-2016-8630

https://access.redhat.com/security/cve/cve-2016-8655

https://access.redhat.com/security/cve/cve-2016-9083

https://access.redhat.com/security/cve/cve-2016-9084

Plugin Details

Severity: High

ID: 97510

File Name: redhat-RHSA-2017-0387.nasl

Version: 3.11

Type: local

Agent: unix

Published: 3/3/2017

Updated: 10/24/2019

Dependencies: ssh_get_info.nasl, linux_alt_patch_detect.nasl

Risk Information

Risk Factor: High

VPR Score: 8.9

CVSS v2.0

Base Score: 7.2

Temporal Score: 6.3

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

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

CVSS v3.0

Base Score: 7.8

Temporal Score: 7.5

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

Temporal Vector: E:H/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: 3/2/2017

Vulnerability Publication Date: 11/28/2016

Exploitable With

Core Impact

Metasploit (AF_PACKET chocobo_root Privilege Escalation)

Reference Information

CVE: CVE-2016-8630, CVE-2016-8655, CVE-2016-9083, CVE-2016-9084

RHSA: 2017:0387