This kernel update is based on the upstream 4.14.70 and adds additional fixes for the L1TF security issues. It also fixes at least the following security issues:
Linux kernel from versions 3.9 and up, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments (CVE-2018-5391, FragmentSmack).
A security flaw was found in the ipfragreasm() function in net/ipv4/ipfragment.c in the Linux kernel caused by fixes for CVE-2018-5391, which can cause a later system crash in ipdo_fragment(). With certain non-default, but non-rare, configuration of a victim host, an attacker can trigger this crash remotely, thus leading to a remote denial-of-service (CVE-2018-14641).
An issue was discovered in the Linux kernel through 4.18.8. The vmacacheflushall function in mm/vmacache.c mishandles sequence number overflows. An attacker can trigger a use-after-free (and possibly gain privileges) via certain thread creation, map, unmap, invalidation, and dereference operations (CVE-2018-17182).
Other fixes in this update: * drm: fix use of freed memory in drmmodesetcrtc * drm/i915: Apply the GTT write flush for all !llc machines * net/tls: Set count of SG entries if skallocsg returns -ENOSPC (fixes a kernel crash) * pinctrl/amd: only handle irq if it is pending and unmasked (possible real fix for the interrupt storm on Ryzen platform)
For other uptstream fixes in this update, see the referenced changelog.