Updated kernel-linus packages fix security vulnerabilities

This kernel-linus update is based on upstream 5.15.6 and fixes at least the following security issues: A vulnerability was found in Linux kernel, where a use-after-frees in nouveau’s postclose() handler could happen if removing device (that is not common to remove video card physically without power-off, but same happens if “unbind” the driver) (CVE-2020-27820). A race condition when the eBPF map is frozen (CVE-2021-4001). A memory leak flaw in the Linux kernel’s hugetlbfs memory usage was found in the way the user maps some regions of memory twice using shmget() which are aligned to PUD alignment with the fault of some of the memory pages. A local user could use this flaw to get unauthorized access to some data (CVE-2021-4002). For other upstream fixes, see the referenced changelogs.