[RHSA-2017:0931-01] Important: kernel-rt security and bug fix update

[news 28]

-----BEGIN PGP SIGNED MESSAGE-----

Hash: SHA1

 

=====================================================================

Red Hat Security Advisory

 

Synopsis: Important: kernel-rt security and bug fix update

Advisory ID: RHSA-2017:0931-01

Product: Red Hat Enterprise Linux

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

Issue date: 2017-04-12

CVE Names: CVE-2016-8650 CVE-2016-9793 CVE-2017-2618

CVE-2017-2636

=====================================================================

 

1. Summary:

 

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.

 

2. Relevant releases/architectures:

 

Red Hat Enterprise Linux Realtime (v. 7) - noarch, x86_64

Red Hat Enterprise Linux for Real Time for NFV (v. 7) - noarch, x86_64

 

3. Description:

 

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)

 

4. Solution:

 

For details on how to apply this update, which includes the changes

described in this advisory, refer to:

 

https://access.redhat.com/articles/11258

 

The system must be rebooted for this update to take effect.

 

5. Bugs fixed (https://bugzilla.redhat.com/):

 

1395187 - CVE-2016-8650 kernel: Null pointer dereference via keyctl

1402013 - CVE-2016-9793 kernel: Signed overflow for SO_{SND|RCV}BUFFORCE

1419916 - CVE-2017-2618 kernel: Off-by-one error in selinux_setprocattr (/proc/self/attr/fscreate)

1428319 - CVE-2017-2636 kernel: Race condition access to n_hdlc.tbuf causes double free in n_hdlc_release()

1430749 - kernel-rt: update to the RHEL7.3.z batch#4 source tree [RT-7.3.z]

 

6. Package List:

 

Red Hat Enterprise Linux for Real Time for NFV (v. 7):

 

Source:

kernel-rt-3.10.0-514.16.1.rt56.437.el7.src.rpm

 

noarch:

kernel-rt-doc-3.10.0-514.16.1.rt56.437.el7.noarch.rpm

 

x86_64:

kernel-rt-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-kvm-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-kvm-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debuginfo-common-x86_64-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-kvm-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-kvm-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-kvm-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-kvm-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

 

Red Hat Enterprise Linux Realtime (v. 7):

 

Source:

kernel-rt-3.10.0-514.16.1.rt56.437.el7.src.rpm

 

noarch:

kernel-rt-doc-3.10.0-514.16.1.rt56.437.el7.noarch.rpm

 

x86_64:

kernel-rt-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debug-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-debuginfo-common-x86_64-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

kernel-rt-trace-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm

 

These packages are GPG signed by Red Hat for security. Our key and

details on how to verify the signature are available from

https://access.redhat.com/security/team/key/

 

7. References:

 

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

https://access.redhat.com/security/updates/classification/#important

 

8. Contact:

 

The Red Hat security contact is . More contact

details at https://access.redhat.com/security/team/contact/

 

Copyright 2017 Red Hat, Inc.

-----BEGIN PGP SIGNATURE-----

Version: GnuPG v1

 

iD8DBQFY7jjUXlSAg2UNWIIRAvx4AJ0UGk1zTaNQOjqhPxzDBAnSVe0UWACfeNls

kwrQgjLNJxXW/CVLujHvI7M=

=zagv

-----END PGP SIGNATURE-----

 

 

--