Synopsis

Important: kernel security update

Type/Severity

Security Advisory: Important

Topic

An update for kernel is now available for Red Hat Enterprise Linux 6.6 Advanced 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.

Description

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

Security Fix(es):

• A flaw was found in the implementation of the "fill buffer", a mechanism used by modern CPUs when a cache-miss is made on L1 CPU cache. If an attacker can generate a load operation that would create a page fault, the execution will continue speculatively with incorrect data from the fill buffer while the data is fetched from higher level caches. This response time can be measured to infer data in the fill buffer. (CVE-2018-12130)
  
• Modern Intel microprocessors implement hardware-level micro-optimizations to improve the performance of writing data back to CPU caches. The write operation is split into STA (STore Address) and STD (STore Data) sub-operations. These sub-operations allow the processor to hand-off address generation logic into these sub-operations for optimized writes. Both of these sub-operations write to a shared distributed processor structure called the 'processor store buffer'. As a result, an unprivileged attacker could use this flaw to read private data resident within the CPU's processor store buffer. (CVE-2018-12126)
  
• Microprocessors use a ‘load port’ subcomponent to perform load operations from memory or IO. During a load operation, the load port receives data from the memory or IO subsystem and then provides the data to the CPU registers and operations in the CPU’s pipelines. Stale load operations results are stored in the 'load port' table until overwritten by newer operations. Certain load-port operations triggered by an attacker can be used to reveal data about previous stale requests leaking data back to the attacker via a timing side-channel. (CVE-2018-12127)
  
• Uncacheable memory on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. (CVE-2019-11091)
  

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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.

Affected Products

• Red Hat Enterprise Linux Server - AUS 6.6 x86_64

Fixes

• BZ - 1646781 - CVE-2018-12126 hardware: Microarchitectural Store Buffer Data Sampling (MSBDS)
• BZ - 1646784 - CVE-2018-12130 hardware: Microarchitectural Fill Buffer Data Sampling (MFBDS)
• BZ - 1667782 - CVE-2018-12127 hardware: Micro-architectural Load Port Data Sampling - Information Leak (MLPDS)
• BZ - 1705312 - CVE-2019-11091 hardware: Microarchitectural Data Sampling Uncacheable Memory (MDSUM)

CVEs

• CVE-2018-12126
• CVE-2018-12127
• CVE-2018-12130
• CVE-2019-11091

References

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

Red Hat Enterprise Linux Server - AUS 6.6

SRPM
kernel-2.6.32-504.78.2.el6.src.rpm	SHA-256: dd5a025d2c77e3ad7452c4572850c76d0960685cc1221379ef4fbb8221060388
x86_64
kernel-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: f7434c90d419d347b7b0543334f59c68dba52713634bc4851aeeab21482ce3bc
kernel-abi-whitelists-2.6.32-504.78.2.el6.noarch.rpm	SHA-256: 8f27f48fb69909e3638945729052c0a244b7f1a8c03f959ef9e14e743a3cd7c6
kernel-debug-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: f44cca0eacb7ab07a4a66f230c0c153f7c842eb7107289c7e7ce0d47a3f697c8
kernel-debug-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 83751c4961526271973c7b67af0b686f34d7b934d682165dd6a0ec2b616fd1a3
kernel-debug-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 83751c4961526271973c7b67af0b686f34d7b934d682165dd6a0ec2b616fd1a3
kernel-debug-devel-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 930c5447dedee4009a797ec52943c849e13d226d263822abdd11e611d8c1443a
kernel-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: ef625f199096308b07e6996d0a5f9ee048182560d00fc427e39b113f11db9bf4
kernel-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: ef625f199096308b07e6996d0a5f9ee048182560d00fc427e39b113f11db9bf4
kernel-debuginfo-common-x86_64-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 6e1799a0e31850d24059a95e7d5cadd56654596cb5ffff86c9fab93ee0388033
kernel-debuginfo-common-x86_64-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 6e1799a0e31850d24059a95e7d5cadd56654596cb5ffff86c9fab93ee0388033
kernel-devel-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 0d24e07b44f17d4fb2d4ff4df3709007b3d0ea35916a2560d734b0e210d10865
kernel-doc-2.6.32-504.78.2.el6.noarch.rpm	SHA-256: eacb161c513709f5d15353ceaca832b849ad17e15ab930e5e8cdac66ff5412e3
kernel-firmware-2.6.32-504.78.2.el6.noarch.rpm	SHA-256: f549c2440c4b4599a6f985fe0a9db67c9b0f0acd0d85be35259f0d812a3dd4d9
kernel-headers-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: fd3c7545a2c364d276fff5ee4b611b3b6569a87adc47195d4191239d6009e559
perf-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 87c438ef7969ce866dab5e9b9583d99f11f639f8f491e24f7367d414d0f0e8ec
perf-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 8b7b18d0f28e8eab960d433c101315ec768720a1e178df1066aad56b619f9f53
perf-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 8b7b18d0f28e8eab960d433c101315ec768720a1e178df1066aad56b619f9f53
python-perf-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: bd2959ee953ae5b08408836637d2c5850ea1c2515a3632bc84ea8087a99c6a74
python-perf-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 8f1dfd2ad7e6715ffda8762a19e9d6556a1001389b361eedb863f8656a269929
python-perf-debuginfo-2.6.32-504.78.2.el6.x86_64.rpm	SHA-256: 8f1dfd2ad7e6715ffda8762a19e9d6556a1001389b361eedb863f8656a269929