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):

• Kernel: KVM: potential use-after-free via kvm_ioctl_create_device() (CVE-2019-6974)
• Kernel: KVM: nVMX: use-after-free of the hrtimer for emulation of the preemption timer (CVE-2019-7221)

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):

• VM hangs on RHEL rt-kernel and OSP 13 [rhel-7.6.z] (BZ#1688673)
• kernel-rt: update to the RHEL7.6.z batch#4 source tree (BZ#1689417)

Users of kernel are advised to upgrade to these updated packages, which fix these bugs.

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 - 1671904 - CVE-2019-7221 Kernel: KVM: nVMX: use-after-free of the hrtimer for emulation of the preemption timer
• BZ - 1671913 - CVE-2019-6974 Kernel: KVM: potential use-after-free via kvm_ioctl_create_device()
• BZ - 1688673 - VM hangs on RHEL rt-kernel and OSP 13 [rhel-7.6.z]
• BZ - 1689417 - kernel-rt: update to the RHEL7.6.z batch#4 source tree

CVEs

• CVE-2019-6974
• CVE-2019-7221

References