This kernel-linus update is based on upstream 4.9.40 and fixes at least the following security issues:
Linux kernel built with the VirtIO GPU driver(CONFIGDRMVIRTIOGPU) support is vulnerable to a memory leakage issue. It could occur while creating a virtio gpu object in virtiogpuobjectcreate(). A user/process could use this flaw to leak host kernel memory potentially resulting in Dos (CVE-2017-10810).
It also contains followup fixes to the Stack Clash (CVE-2017-1000370, CVE-2017-1000371) security issues resolved in kernels released at end of June, 2017.
Other Mageia kernel specific fixes in this updates: - enable support for NFS41 and NFS42 (mga#21182)
For other upstream fixes in this update, read the referenced changelogs.