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RedHat: RHSA-2019-1483-01 Important: Kernel Bug Fix Denial of Service

red hat
Calendar Grey June 17, 2019
Dist Redhat Esm H88
This essential notice highlights several core system fixes, encompassing major bug resolutions and security upgrades for CentOS.
An update for kernel is now available for Red Hat Enterprise Linux 7.4 Extended Update Support

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.

Summary

The kernel packages contain the Linux kernel, the core of any Linux operating system.
Security Fix(es):
* An integer overflow flaw was found in the way the Linux kernel's networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel's socket buffer (SKB) data structure becomes fragmented. Each fragment is about TCP maximum segment size (MSS) bytes. To efficiently process SACK blocks, the Linux kernel merges multiple fragmented SKBs into one, potentially overflowing the variable holding the number of segments. A remote attacker could use this flaw to crash the Linux kernel by sending a crafted sequence of SACK segments on a TCP connection with small value of TCP MSS, resulting in a denial of service (DoS). (CVE-2019-11477)
* kernel: race condition in snd_seq_write() may lead to UAF or OOB-access (CVE-2018-7566)
* kernel: Race condition in sound system can lead to denial of service (CVE-2018-1000004)
* Kernel: tcp: excessive resource consumption while processing SACK blocks allows remote denial of service (CVE-2019-11478)
* Kernel: tcp: excessive resource consumption for TCP connections with low MSS allows remote denial of service (CVE-2019-11479)
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.
Bug Fix(es):
* Mistmach between 'tty->termios->c_lflag' and 'ldata->icanon' for 'ICANON' (BZ#1708061)
* RHEL7: rwsem reader/writer mutual exclusion guarantee may not work (BZ#1709702)
* hardened usercopy is causing crash (BZ#1712311)
* [RHEL7] md_clear flag missing from /proc/cpuinfo on late microcode update (BZ#1712991)
* [RHEL7] MDS mitigations are not enabled after double microcode update (BZ#1712996)
* WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:90 __static_key_slow_dec+0xa6/0xb0 (BZ#1713002)
* [debug kernel] [x86_64]INFO: possible circular locking dependency detected (BZ#1715326)
* RHEL-7.7: tty: termios_rwsem possible deadlock (BZ#1715329)
Enhancement(s):
* [MCHP 7.7 FEAT] Update smartpqi driver to latest upstream (BZ#1709467)

Topics%20covered

Topics Covered

security advisory denial of service Red Hat kernel update bug fix integer overflow tcp attack

References

https://access.redhat.com/security/cve/CVE-2018-7566 https://access.redhat.com/security/cve/CVE-2018-1000004 https://access.redhat.com/security/cve/CVE-2019-11477 https://access.redhat.com/security/cve/CVE-2019-11478 https://access.redhat.com/security/cve/CVE-2019-11479 https://access.redhat.com/security/updates/classification/#important https://access.redhat.com/security/vulnerabilities/tcpsack

Package List

Red Hat Enterprise Linux ComputeNode EUS (v. 7.4):
Source: kernel-3.10.0-693.50.3.el7.src.rpm
noarch: kernel-abi-whitelists-3.10.0-693.50.3.el7.noarch.rpm kernel-doc-3.10.0-693.50.3.el7.noarch.rpm
x86_64: kernel-3.10.0-693.50.3.el7.x86_64.rpm kernel-debug-3.10.0-693.50.3.el7.x86_64.rpm kernel-debug-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm kernel-debug-devel-3.10.0-693.50.3.el7.x86_64.rpm kernel-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-693.50.3.el7.x86_64.rpm kernel-devel-3.10.0-693.50.3.el7.x86_64.rpm kernel-headers-3.10.0-693.50.3.el7.x86_64.rpm kernel-tools-3.10.0-693.50.3.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm kernel-tools-libs-3.10.0-693.50.3.el7.x86_64.rpm perf-3.10.0-693.50.3.el7.x86_64.rpm perf-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm python-perf-3.10.0-693.50.3.el7.x86_64.rpm python-perf-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.4):
x86_64: kernel-debug-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm kernel-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm kernel-debuginfo-common-x86_64-3.10.0-693.50.3.el7.x86_64.rpm kernel-tools-debuginfo-3.10.0-693.50.3.el7.x86_64.rpm kernel-tools-libs-devel-3.10.0-693.50.3.el7.x86_64.rpm

Read the Full Advisory


Severity
important
Lowest
Low
Medium
High
Critical

Advisory ID: RHSA-2019:1483-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2019:1483
Issue date: 2019-06-17

Topic

An update for kernel is now available for Red Hat Enterprise Linux 7.4Extended Update Support.Red Hat Product Security has rated this update as having a security impactof Important. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available for each vulnerabilityfrom the CVE link(s) in the References section.

Topics%20covered

Topics Covered

security advisory denial of service Red Hat kernel update bug fix integer overflow tcp attack

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

Bugs Fixed

1535315 - CVE-2018-1000004 kernel: Race condition in sound system can lead to denial of service

1550142 - CVE-2018-7566 kernel: race condition in snd_seq_write() may lead to UAF or OOB-access

1719123 - CVE-2019-11477 Kernel: tcp: integer overflow while processing SACK blocks allows remote denial of service

1719128 - CVE-2019-11478 Kernel: tcp: excessive resource consumption while processing SACK blocks allows remote denial of service

1719129 - CVE-2019-11479 Kernel: tcp: excessive resource consumption for TCP connections with low MSS allows remote denial of service

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