RedHat: RHSA-2018-2791:01 Important: kernel security and bug fix update
Summary
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)
* A flaw named FragmentSmack was found in the way the Linux kernel handled
reassembly of fragmented IPv4 and IPv6 packets. A remote attacker could use
this flaw to trigger time and calculation expensive fragment reassembly
algorithm by sending specially crafted packets which could lead to a CPU
saturation and hence a denial of service on the system. (CVE-2018-5391)
* kernel: mm: use-after-free in do_get_mempolicy function allows local DoS
or other unspecified impact (CVE-2018-10675)
For more details about the security issue(s), including the impact, a CVSS
score, and other related information, refer to the CVE page(s) listed in
the References section.
Red Hat would like to thank Juha-Matti Tilli (Aalto University - Department
of Communications and Networking and Nokia Bell Labs) for reporting
CVE-2018-5390 and CVE-2018-5391.
Bug Fix(es):
* After updating the system to prevent the L1 Terminal Fault (L1TF)
vulnerability, only one thread was detected on systems that offer
processing of two threads on a single processor core. With this update, the
"__max_smt_threads()" function has been fixed. As a result, both threads
are now detected correctly in the described situation. (BZ#1625330)
Summary
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.
References
https://access.redhat.com/security/cve/CVE-2018-5390 https://access.redhat.com/security/cve/CVE-2018-5391 https://access.redhat.com/security/cve/CVE-2018-10675 https://access.redhat.com/security/updates/classification/#important
Package List
Red Hat Enterprise Linux Server AUS (v. 6.4):
Source:
kernel-2.6.32-358.93.1.el6.src.rpm
noarch:
kernel-doc-2.6.32-358.93.1.el6.noarch.rpm
kernel-firmware-2.6.32-358.93.1.el6.noarch.rpm
x86_64:
kernel-2.6.32-358.93.1.el6.x86_64.rpm
kernel-debug-2.6.32-358.93.1.el6.x86_64.rpm
kernel-debug-debuginfo-2.6.32-358.93.1.el6.x86_64.rpm
kernel-debug-devel-2.6.32-358.93.1.el6.x86_64.rpm
kernel-debuginfo-2.6.32-358.93.1.el6.x86_64.rpm
kernel-debuginfo-common-x86_64-2.6.32-358.93.1.el6.x86_64.rpm
kernel-devel-2.6.32-358.93.1.el6.x86_64.rpm
kernel-headers-2.6.32-358.93.1.el6.x86_64.rpm
perf-2.6.32-358.93.1.el6.x86_64.rpm
perf-debuginfo-2.6.32-358.93.1.el6.x86_64.rpm
python-perf-debuginfo-2.6.32-358.93.1.el6.x86_64.rpm
Red Hat Enterprise Linux Server Optional AUS (v. 6.4):
Source:
kernel-2.6.32-358.93.1.el6.src.rpm
x86_64:
kernel-debug-debuginfo-2.6.32-358.93.1.el6.x86_64.rpm
kernel-debuginfo-2.6.32-358.93.1.el6.x86_64.rpm
kernel-debuginfo-common-x86_64-2.6.32-358.93.1.el6.x86_64.rpm
perf-debuginfo-2.6.32-358.93.1.el6.x86_64.rpm
python-perf-2.6.32-358.93.1.el6.x86_64.rpm
python-perf-debuginfo-2.6.32-358.93.1.el6.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/
Topic
An update for kernel is now available for Red Hat Enterprise Linux 6.4Advanced 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.
Topic
Relevant Releases Architectures
Red Hat Enterprise Linux Server AUS (v. 6.4) - noarch, x86_64
Red Hat Enterprise Linux Server Optional AUS (v. 6.4) - x86_64
Bugs Fixed
1575065 - CVE-2018-10675 kernel: mm: use-after-free in do_get_mempolicy function allows local DoS or other unspecified impact
1601704 - CVE-2018-5390 kernel: TCP segments with random offsets allow a remote denial of service (SegmentSmack)
1609664 - CVE-2018-5391 kernel: IP fragments with random offsets allow a remote denial of service (FragmentSmack)
