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

High Nessus Plugin ID 97510


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


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)


Update the affected packages.

See Also






Plugin Details

Severity: High

ID: 97510

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

Version: $Revision: 3.2 $

Type: local

Agent: unix

Published: 2017/03/03

Modified: 2017/03/07

Dependencies: 12634

Risk Information

Risk Factor: High


Base Score: 7.2

Temporal Score: 6.5

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

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


Base Score: 7.8

Temporal Score: 7.4

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:X/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-trace, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-devel, 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: 2017/03/02

Exploitable With

Core Impact

Reference Information

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

OSVDB: 146370, 146377, 147015, 148164

RHSA: 2017:0387