RHEL 7 : kernel-rt (RHSA-2017:0091)

This script is Copyright (C) 2017 Tenable Network Security, Inc.


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 use-after-free vulnerability was found in the kernel's socket
recvmmsg subsystem. This may allow remote attackers to corrupt memory
and may allow execution of arbitrary code. This corruption takes place
during the error handling routines within __sys_recvmmsg() function.
(CVE-2016-7117, Important)

* A use-after-free vulnerability was found in
tcp_xmit_retransmit_queue and other tcp_* functions. This condition
could allow an attacker to send an incorrect selective acknowledgment
to existing connections, possibly resetting a connection.
(CVE-2016-6828, Moderate)

* A flaw was found in the Linux kernel's implementation of sctp
protocol in which a remote attacker can trigger an out of bounds read
with an offset of up to 64kB. This may panic the machine with a
page-fault. (CVE-2016-9555, Moderate)

Bug Fix(es) :

* The kernel-rt packages have been upgraded to the 3.10.0-514.6.1
source tree, which provides a number of bug fixes over the previous
version. (BZ#1401863)

* Previously, the device mapper (DM) subsystem was not notified that
the real-time kernel changes the way preemption works with spinlocks.
This caused a kernel panic when the dm-multipath kernel module was
loaded because the interrupt request (IRQ) check was invalid on the
real-time kernel. This check has been corrected enabling the system to
boot correctly with the dm-multipath module enabled. (BZ#1400930)

* Unlike the standard Linux kernel, the real-time kernel does not
disable interrupts inside the Interrupt Service Routines driver.
Because of this difference, a New API (NAPI) function for turning
interrupt requests (IRQ) off was actually being called with IRQs
enabled. Consequently, the NAPI poll list was being corrupted, causing
improper networking card operation and potential kernel hangs. With
this update, the NAPI function has been corrected to force
modifications of the poll list to be protected allowing proper
operation of the networking card drivers. (BZ#1402837)

See also :

https://www.redhat.com/security/data/cve/CVE-2016-6828.html
https://www.redhat.com/security/data/cve/CVE-2016-7117.html
https://www.redhat.com/security/data/cve/CVE-2016-9555.html
http://www.nessus.org/u?e4086253
http://rhn.redhat.com/errata/RHSA-2017-0091.html

Solution :

Update the affected packages.

Risk factor :

Critical / CVSS Base Score : 10.0
(CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C)
CVSS Temporal Score : 7.4
(CVSS2#E:U/RL:OF/RC:C)
Public Exploit Available : false

Family: Red Hat Local Security Checks

Nessus Plugin ID: 96594 ()

Bugtraq ID:

CVE ID: CVE-2016-6828
CVE-2016-7117
CVE-2016-9555

Ready to Amp Up Your Nessus Experience?

Get Nessus Professional to scan unlimited IPs, run compliance checks & more

Buy Nessus Professional Now