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 MRG 2.

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: Use-after-free vulnerability in DCCP socket (CVE-2017-8824, Important)
• kernel: v4l2: disabled memory access protection mechanism allowing privilege escalation (CVE-2017-13166, Important)
• kernel: Incorrect type conversion for size during dma allocation (CVE-2017-9725, Moderate)
• kernel: Use-after-free in snd_seq_ioctl_create_port() (CVE-2017-15265, Moderate)
• kernel: Missing namespace check in net/netlink/af_netlink.c allows for network monitors to observe systemwide activity (CVE-2017-17449, Moderate)
• kernel: netfilter: use-after-free in tcpmss_mangle_packet function in net/netfilter/xt_TCPMSS.c (CVE-2017-18017, Moderate)
• kernel: Stack information leak in the EFS element (CVE-2017-1000410, Moderate)

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 Mohamed Ghannam for reporting CVE-2017-8824 and Armis Labs for reporting CVE-2017-1000410.

Bug Fix(es):

• The kernel-rt packages have been upgraded to version 3.10.0-693.25.2.rt56.612, which provides a number of security and bug fixes over the previous version. (BZ#1549731)
• Intel Core X-Series (Skylake) processors use a hardcoded Time Stamp Counter (TSC) frequency of 25 MHz. In some cases this can be imprecise and lead to timing-related problems such as time drift, timers being triggered early, or TSC clock instability. This update mitigates these problems by no longer using the "native_calibrate_tsc()" function to define the TSC frequency. Refined calibration is now used to update the clock rate accordingly in these cases. (BZ#1547854)

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

• MRG Realtime 2 x86_64

Fixes

• BZ - 1489088 - CVE-2017-9725 kernel: Incorrect type conversion for size during dma allocation
• BZ - 1501878 - CVE-2017-15265 kernel: Use-after-free in snd_seq_ioctl_create_port()
• BZ - 1519160 - CVE-2017-1000410 kernel: Stack information leak in the EFS element
• BZ - 1519591 - CVE-2017-8824 kernel: Use-after-free vulnerability in DCCP socket
• BZ - 1525762 - CVE-2017-17449 kernel: Missing namespace check in net/netlink/af_netlink.c allows for network monitors to observe systemwide activity
• BZ - 1531135 - CVE-2017-18017 kernel: netfilter: use-after-free in tcpmss_mangle_packet function in net/netfilter/xt_TCPMSS.c
• BZ - 1547854 - Latest rt56 real time kernel on Intel i9 has broken TSC
• BZ - 1548412 - CVE-2017-13166 kernel: v4l2: disabled memory access protection mechanism allowing privilege escalation
• BZ - 1549731 - update the MRG 2.5.z 3.10 kernel-rt sources

CVEs

• CVE-2017-8824
• CVE-2017-9725
• CVE-2017-13166
• CVE-2017-15265
• CVE-2017-17449
• CVE-2017-18017
• CVE-2017-1000410

References