[RHSA-2017:0387-01] Important: kernel-rt security and bug fix update

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Red Hat Security Advisory

 

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

Advisory ID: RHSA-2017:0387-01

Product: Red Hat Enterprise Linux

Advisory URL: https://rhn.redhat.com/errata/RHSA-2017-0387.html

Issue date: 2017-03-02

CVE Names: CVE-2016-8630 CVE-2016-8655 CVE-2016-9083

CVE-2016-9084

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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):

 

* 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)

 

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/):

 

1389258 - CVE-2016-9083 kernel: State machine confusion bug in vfio driver leading to memory corruption

1389259 - CVE-2016-9084 kernel: Integer overflow when using kzalloc in vfio driver

1393350 - CVE-2016-8630 kernel: kvm: x86: NULL pointer dereference during instruction decode

1400019 - CVE-2016-8655 kernel: Race condition in packet_set_ring leads to use after free

1415172 - kernel-rt: update to the RHEL7.3.z batch#3 source tree [rt-7.3.z]

 

6. Package List:

 

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

 

Source:

kernel-rt-3.10.0-514.10.2.rt56.435.el7.src.rpm

 

noarch:

kernel-rt-doc-3.10.0-514.10.2.rt56.435.el7.noarch.rpm

 

x86_64:

kernel-rt-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-devel-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-kvm-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-kvm-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debuginfo-common-x86_64-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-devel-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-kvm-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-kvm-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-devel-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-kvm-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-kvm-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

 

Red Hat Enterprise Linux Realtime (v. 7):

 

Source:

kernel-rt-3.10.0-514.10.2.rt56.435.el7.src.rpm

 

noarch:

kernel-rt-doc-3.10.0-514.10.2.rt56.435.el7.noarch.rpm

 

x86_64:

kernel-rt-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debug-devel-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-debuginfo-common-x86_64-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-devel-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-debuginfo-3.10.0-514.10.2.rt56.435.el7.x86_64.rpm

kernel-rt-trace-devel-3.10.0-514.10.2.rt56.435.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-2016-8630

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

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.

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