[RHSA-2018:2776-01] Important: kernel security and bug fix update

Tue Sep 25 20:47:17 UTC 2018

An update for kernel is now available for Red Hat Enterprise Linux 7.4
Extended Update Support.

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 ComputeNode EUS (v. 7.4) - noarch, x86_64
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.4) - x86_64
Red Hat Enterprise Linux Server EUS (v. 7.4) - noarch, ppc64, ppc64le, s390x, x86_64
Red Hat Enterprise Linux Server Optional EUS (v. 7.4) - ppc64, ppc64le, x86_64

3. Description:

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

Security Fix(es):

* A flaw named SegmentSmack was found in the way the Linux kernel handled
specially crafted TCP packets. A remote attacker could use this flaw to
trigger time and calculation expensive calls to tcp_collapse_ofo_queue()
and tcp_prune_ofo_queue() functions by sending specially modified packets
within ongoing TCP sessions which could lead to a CPU saturation and hence
a denial of service on the system. Maintaining the denial of service
condition requires continuous two-way TCP sessions to a reachable open
port, thus the attacks cannot be performed using spoofed IP addresses.
(CVE-2018-5390)

Red Hat would like to thank Juha-Matti Tilli (Aalto University - Department
of Communications and Networking and Nokia Bell Labs) for reporting this
issue.

Bug Fix(es):

* Previously, making the total buffer size bigger than the memory size for
early allocation through the trace_buf_size boot option, made the system
become unresponsive at the boot stage. This update introduces a change in
the early memory allocation. As a result, the system no longer hangs in the
above described scenario. (BZ#1588365)

* When inserting objects with the same keys, made the rhlist implementation
corrupt the chain pointers. As a consequence, elements were missing on
removal and traversal. This patch updates the chain pointers correctly. As
a result, there are no missing elements on removal and traversal in the
above-described scenario. (BZ#1601008)

* Previously, the kernel source code was missing support to report the
Speculative Store Bypass Disable (SSBD) vulnerability status on IBM Power
Systems and the little-endian variants of IBM Power Systems. As a
consequence, the /sys/devices/system/cpu/vulnerabilities/spec_store_bypass
file incorrectly reported "Not affected" on both CPU architectures. This
fix updates the kernel source code to properly report the SSBD status
either as "Vulnerable" or "Mitigation: Kernel entry/exit barrier (TYPE)"
where TYPE is one of "eieio", "hwsync", "fallback", or "unknown".
(BZ#1612352)

* Previously, the early microcode updater in the kernel was trying to
perform a microcode update on virtualized guests. As a consequence, the
virtualized guests sometimes mishandled the request to perform the
microcode update and became unresponsive in the early boot stage. This
update applies an upstream patch to avoid the early microcode update when
running under a hypervisor. As a result, no kernel freezes appear in the
described scenario. (BZ#1618389)

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/):

1601704 - CVE-2018-5390 kernel: TCP segments with random offsets allow a remote denial of service (SegmentSmack)

6. Package List:

Red Hat Enterprise Linux ComputeNode EUS (v. 7.4):

Source:
kernel-3.10.0-693.39.1.el7.src.rpm

noarch:
kernel-abi-whitelists-3.10.0-693.39.1.el7.noarch.rpm
kernel-doc-3.10.0-693.39.1.el7.noarch.rpm

x86_64:
kernel-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debug-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debug-devel-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-693.39.1.el7.x86_64.rpm
kernel-devel-3.10.0-693.39.1.el7.x86_64.rpm
kernel-headers-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-libs-3.10.0-693.39.1.el7.x86_64.rpm
perf-3.10.0-693.39.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
python-perf-3.10.0-693.39.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm

Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.4):

x86_64:
kernel-debug-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-693.39.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm

Red Hat Enterprise Linux Server EUS (v. 7.4):

Source:
kernel-3.10.0-693.39.1.el7.src.rpm

noarch:
kernel-abi-whitelists-3.10.0-693.39.1.el7.noarch.rpm
kernel-doc-3.10.0-693.39.1.el7.noarch.rpm

ppc64:
kernel-3.10.0-693.39.1.el7.ppc64.rpm
kernel-bootwrapper-3.10.0-693.39.1.el7.ppc64.rpm
kernel-debug-3.10.0-693.39.1.el7.ppc64.rpm
kernel-debug-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
kernel-debug-devel-3.10.0-693.39.1.el7.ppc64.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
kernel-debuginfo-common-ppc64-3.10.0-693.39.1.el7.ppc64.rpm
kernel-devel-3.10.0-693.39.1.el7.ppc64.rpm
kernel-headers-3.10.0-693.39.1.el7.ppc64.rpm
kernel-tools-3.10.0-693.39.1.el7.ppc64.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
kernel-tools-libs-3.10.0-693.39.1.el7.ppc64.rpm
perf-3.10.0-693.39.1.el7.ppc64.rpm
perf-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
python-perf-3.10.0-693.39.1.el7.ppc64.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm

ppc64le:
kernel-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-bootwrapper-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-debug-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-debug-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-debuginfo-common-ppc64le-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-devel-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-headers-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-tools-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-tools-libs-3.10.0-693.39.1.el7.ppc64le.rpm
perf-3.10.0-693.39.1.el7.ppc64le.rpm
perf-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
python-perf-3.10.0-693.39.1.el7.ppc64le.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm

s390x:
kernel-3.10.0-693.39.1.el7.s390x.rpm
kernel-debug-3.10.0-693.39.1.el7.s390x.rpm
kernel-debug-debuginfo-3.10.0-693.39.1.el7.s390x.rpm
kernel-debug-devel-3.10.0-693.39.1.el7.s390x.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.s390x.rpm
kernel-debuginfo-common-s390x-3.10.0-693.39.1.el7.s390x.rpm
kernel-devel-3.10.0-693.39.1.el7.s390x.rpm
kernel-headers-3.10.0-693.39.1.el7.s390x.rpm
kernel-kdump-3.10.0-693.39.1.el7.s390x.rpm
kernel-kdump-debuginfo-3.10.0-693.39.1.el7.s390x.rpm
kernel-kdump-devel-3.10.0-693.39.1.el7.s390x.rpm
perf-3.10.0-693.39.1.el7.s390x.rpm
perf-debuginfo-3.10.0-693.39.1.el7.s390x.rpm
python-perf-3.10.0-693.39.1.el7.s390x.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.s390x.rpm

x86_64:
kernel-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debug-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debug-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debug-devel-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-693.39.1.el7.x86_64.rpm
kernel-devel-3.10.0-693.39.1.el7.x86_64.rpm
kernel-headers-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-libs-3.10.0-693.39.1.el7.x86_64.rpm
perf-3.10.0-693.39.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
python-perf-3.10.0-693.39.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm

Red Hat Enterprise Linux Server Optional EUS (v. 7.4):

ppc64:
kernel-debug-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
kernel-debuginfo-common-ppc64-3.10.0-693.39.1.el7.ppc64.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
kernel-tools-libs-devel-3.10.0-693.39.1.el7.ppc64.rpm
perf-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.ppc64.rpm

ppc64le:
kernel-debug-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-debug-devel-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-debuginfo-common-ppc64le-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
kernel-tools-libs-devel-3.10.0-693.39.1.el7.ppc64le.rpm
perf-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm
python-perf-debuginfo-3.10.0-693.39.1.el7.ppc64le.rpm

x86_64:
kernel-debug-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-debuginfo-common-x86_64-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
kernel-tools-libs-devel-3.10.0-693.39.1.el7.x86_64.rpm
perf-debuginfo-3.10.0-693.39.1.el7.x86_64.rpm
python-perf-debuginfo-3.10.0-693.39.1.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-2018-5390
https://access.redhat.com/security/updates/classification/#important

8. Contact:

The Red Hat security contact is <secalert at redhat.com>. More contact
details at https://access.redhat.com/security/team/contact/

Copyright 2018 Red Hat, Inc.
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