(RHSA-2018:1170) Important: kernel-rt security and bug fix update

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)