RedHat: RHSA-2018-2395:01 Important: kernel-rt security and bug fix update
Summary
The kernel-rt packages provide the Real Time Linux Kernel, which enables
fine-tuning for systems with extremely high determinism requirements.
Security Fix(es):
* Modern operating systems implement virtualization of physical memory to
efficiently use available system resources and provide inter-domain
protection through access control and isolation. The L1TF issue was found
in the way the x86 microprocessor designs have implemented speculative
execution of instructions (a commonly used performance optimisation) in
combination with handling of page-faults caused by terminated virtual to
physical address resolving process. As a result, an unprivileged attacker
could use this flaw to read privileged memory of the kernel or other
processes and/or cross guest/host boundaries to read host memory by
conducting targeted cache side-channel attacks. (CVE-2018-3620,
CVE-2018-3646)
* An industry-wide issue was found in the way many modern microprocessor
designs have implemented speculative execution of instructions past bounds
check. The flaw relies on the presence of a precisely-defined instruction
sequence in the privileged code and the fact that memory writes occur to an
address which depends on the untrusted value. Such writes cause an update
into the microprocessor's data cache even for speculatively executed
instructions that never actually commit (retire). As a result, an
unprivileged attacker could use this flaw to influence speculative
execution and/or read privileged memory by conducting targeted cache
side-channel attacks. (CVE-2018-3693)
* 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)
* kernel: crypto: privilege escalation in skcipher_recvmsg function
(CVE-2017-13215)
* kernel: mm: use-after-free in do_get_mempolicy function allows local DoS
or other unspecified impact (CVE-2018-10675)
* kernel: race condition in snd_seq_write() may lead to UAF or OOB access
(CVE-2018-7566)
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 Intel OSSIRT (Intel.com) for reporting
CVE-2018-3620 and CVE-2018-3646; Vladimir Kiriansky (MIT) and Carl
Waldspurger (Carl Waldspurger Consulting) for reporting CVE-2018-3693; and
Juha-Matti Tilli (Aalto University, Department of Communications and
Networking and Nokia Bell Labs) for reporting CVE-2018-5390.
Bug Fix(es):
* The kernel-rt packages have been upgraded to the 3.10.0-862.10.2 source
tree, which provides a number of bug fixes over the previous version.
(BZ#1594915)
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-2017-13215 https://access.redhat.com/security/cve/CVE-2018-3620 https://access.redhat.com/security/cve/CVE-2018-3646 https://access.redhat.com/security/cve/CVE-2018-3693 https://access.redhat.com/security/cve/CVE-2018-5390 https://access.redhat.com/security/cve/CVE-2018-7566 https://access.redhat.com/security/cve/CVE-2018-10675 https://access.redhat.com/security/updates/classification/#important https://access.redhat.com/security/vulnerabilities/L1TF
Package List
Red Hat Enterprise Linux for Real Time for NFV (v. 7):
Source:
kernel-rt-3.10.0-862.11.6.rt56.819.el7.src.rpm
noarch:
kernel-rt-doc-3.10.0-862.11.6.rt56.819.el7.noarch.rpm
x86_64:
kernel-rt-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debug-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debug-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debug-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debug-kvm-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debug-kvm-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-kvm-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-kvm-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-trace-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-trace-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-trace-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-trace-kvm-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-trace-kvm-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
Red Hat Enterprise Linux Realtime (v. 7):
Source:
kernel-rt-3.10.0-862.11.6.rt56.819.el7.src.rpm
noarch:
kernel-rt-doc-3.10.0-862.11.6.rt56.819.el7.noarch.rpm
x86_64:
kernel-rt-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debug-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-debug-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-trace-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm
kernel-rt-trace-devel-3.10.0-862.11.6.rt56.819.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/
![Dist Redhat](/images/distros/dist-redhat.png)
Topic
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 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 Realtime (v. 7) - noarch, x86_64
Red Hat Enterprise Linux for Real Time for NFV (v. 7) - noarch, x86_64
Bugs Fixed
1535173 - CVE-2017-13215 kernel: crypto: privilege escalation in skcipher_recvmsg function
1550142 - CVE-2018-7566 kernel: race condition in snd_seq_write() may lead to UAF or OOB-access
1575065 - CVE-2018-10675 kernel: mm: use-after-free in do_get_mempolicy function allows local DoS or other unspecified impact
1581650 - CVE-2018-3693 Kernel: speculative bounds check bypass store
1585005 - CVE-2018-3646 Kernel: hw: cpu: L1 terminal fault (L1TF)
1594915 - kernel-rt: update to the RHEL7.5.z batch#3 source tree
1601704 - CVE-2018-5390 kernel: TCP segments with random offsets allow a remote denial of service (SegmentSmack)