Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory: Important

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 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-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)

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 for Real Time 7 x86_64
• Red Hat Enterprise Linux for Real Time for NFV 7 x86_64

Fixes

• BZ - 1535173 - CVE-2017-13215 kernel: crypto: privilege escalation in skcipher_recvmsg function
• BZ - 1550142 - CVE-2018-7566 kernel: race condition in snd_seq_write() may lead to UAF or OOB-access
• BZ - 1575065 - CVE-2018-10675 kernel: mm: use-after-free in do_get_mempolicy function allows local DoS or other unspecified impact
• BZ - 1581650 - CVE-2018-3693 Kernel: speculative bounds check bypass store
• BZ - 1585005 - CVE-2018-3646 Kernel: hw: cpu: L1 terminal fault (L1TF)
• BZ - 1594915 - kernel-rt: update to the RHEL7.5.z batch#3 source tree
• BZ - 1601704 - CVE-2018-5390 kernel: TCP segments with random offsets allow a remote denial of service (SegmentSmack)

CVEs

• CVE-2017-13215
• CVE-2018-3620
• CVE-2018-3646
• CVE-2018-3693
• CVE-2018-5390
• CVE-2018-7566
• CVE-2018-10675

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/security/vulnerabilities/L1TF

Red Hat Enterprise Linux for Real Time 7

SRPM
kernel-rt-3.10.0-862.11.6.rt56.819.el7.src.rpm	SHA-256: 0aad162e29348759fb2d2211b45eaaf34b8597bd8fffb70fa5c467ab6d5f71de
x86_64
kernel-rt-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 193bde985cb01475f576a3c5a5f3116a014662ec54f8b6a525aa021f38b19e23
kernel-rt-debug-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 8aaf33215fbaa6d54780a1420deffd9bbe29eda8d478ff070862d46ebb36a2f0
kernel-rt-debug-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 0f98a00dfbc00a6a0265e74f0c0ffc2f8e364579f288bc9cb61cab62e85f88a3
kernel-rt-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: bddf538528cd19369e069c6f202e4ea4b6f8d9b6d1e0e4d48eb626568d80c2b2
kernel-rt-doc-3.10.0-862.11.6.rt56.819.el7.noarch.rpm	SHA-256: 0184a95d37b0ab3242669b65813a3db63db014abe30348b5799eef10fea37760
kernel-rt-trace-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 6c77648cff247d148133ab09596be6dd1caddcaacb0a8474bdc2afb5fdb79668
kernel-rt-trace-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 94ad6e6e28a3a8ce2cef25c7982223b2d0b8572cb10428801b7cec413e539655

Red Hat Enterprise Linux for Real Time for NFV 7

SRPM
kernel-rt-3.10.0-862.11.6.rt56.819.el7.src.rpm	SHA-256: 0aad162e29348759fb2d2211b45eaaf34b8597bd8fffb70fa5c467ab6d5f71de
x86_64
kernel-rt-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 193bde985cb01475f576a3c5a5f3116a014662ec54f8b6a525aa021f38b19e23
kernel-rt-debug-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 8aaf33215fbaa6d54780a1420deffd9bbe29eda8d478ff070862d46ebb36a2f0
kernel-rt-debug-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: fe6330fbc78287ffe9305ea64d78b6bbaaf8576631ccb6a2fae32c70b8ab610f
kernel-rt-debug-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 0f98a00dfbc00a6a0265e74f0c0ffc2f8e364579f288bc9cb61cab62e85f88a3
kernel-rt-debug-kvm-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 7cf096d54bc431d01ebf8ef5ec862974149527dbea845b8c45d1a9d831700d98
kernel-rt-debug-kvm-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: b1de3bde8348a67d6e6f3f00e6aed1344c4461841d300f1f30b9a2c2681cfa98
kernel-rt-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 8d99e5de467d6de97c7f3addb2289fbf3dfde2891e6742b995f43aada6a91eb1
kernel-rt-debuginfo-common-x86_64-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: d0239dfe3bc55ec0c454e4ca98749d17e05bba125c8e2f658ad53ce71edebaf2
kernel-rt-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: bddf538528cd19369e069c6f202e4ea4b6f8d9b6d1e0e4d48eb626568d80c2b2
kernel-rt-doc-3.10.0-862.11.6.rt56.819.el7.noarch.rpm	SHA-256: 0184a95d37b0ab3242669b65813a3db63db014abe30348b5799eef10fea37760
kernel-rt-kvm-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 05afc65c8057c01ab454af166ca76e00bc422b538d5e306994f9806eeae8e977
kernel-rt-kvm-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 68d3a2bc6c1d9e9ed49de0f2cfe5515209a5be9a6f89135b1637d6c0d5c1a3ac
kernel-rt-trace-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 6c77648cff247d148133ab09596be6dd1caddcaacb0a8474bdc2afb5fdb79668
kernel-rt-trace-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 6f8a3a7e0fbbb6fc5a32e0293483746125b1728a2422457947440eecda359028
kernel-rt-trace-devel-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: 94ad6e6e28a3a8ce2cef25c7982223b2d0b8572cb10428801b7cec413e539655
kernel-rt-trace-kvm-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: a172a731001fcab3d22c31d25b00b5a2f18508f4113dfa735ac9829d1e171172
kernel-rt-trace-kvm-debuginfo-3.10.0-862.11.6.rt56.819.el7.x86_64.rpm	SHA-256: aa38e1a3076b97297fc8d915f8a38be8dd5135457bd1472547326154bc6532f6