RHSA-2018:1355 - Security Advisory

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):

• Kernel: KVM: error in exception handling leads to wrong debug stack value (CVE-2018-1087)
• Kernel: error in exception handling leads to DoS (CVE-2018-8897)
• Kernel: ipsec: xfrm: use-after-free leading to potential privilege escalation (CVE-2017-16939)
• kernel: Out-of-bounds write via userland offsets in ebt_entry struct in netfilter/ebtables.c (CVE-2018-1068)
• kernel: ptrace() incorrect error handling leads to corruption and DoS (CVE-2018-1000199)

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 Andy Lutomirski for reporting CVE-2018-1087 and CVE-2018-1000199 and Nick Peterson (Everdox Tech LLC) and Andy Lutomirski for reporting CVE-2018-8897.

Bug Fix(es):

• The kernel-rt packages have been upgraded to the 3.10.0-862.2.3 source tree, which provides a number of bug fixes over the previous version. (BZ#1549768)

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 - 1517220 - CVE-2017-16939 Kernel: ipsec: xfrm: use-after-free leading to potential privilege escalation
• BZ - 1549768 - kernel-rt: update to the RHEL7.5.z batch#1 source tree
• BZ - 1552048 - CVE-2018-1068 kernel: Out-of-bounds write via userland offsets in ebt_entry struct in netfilter/ebtables.c
• BZ - 1566837 - CVE-2018-1087 Kernel: KVM: error in exception handling leads to wrong debug stack value
• BZ - 1567074 - CVE-2018-8897 Kernel: error in exception handling leads to DoS
• BZ - 1568477 - CVE-2018-1000199 kernel: ptrace() incorrect error handling leads to corruption and DoS

CVEs

• CVE-2017-16939
• CVE-2018-1068
• CVE-2018-1087
• CVE-2018-8897
• CVE-2018-1000199

References

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