Security update for the Linux Kernel (Live Patch 18 for SLE 15)

This update for the Linux Kernel 4.12.14-150_52 fixes several issues. The following security issues were fixed: - CVE-2020-29368: Fixed an issue in copy-on-write implementation which could have granted unintended write access because of a race condition in a THP mapcount check (bsc#1179664). - CVE-2021-3347: Fixed a use-after-free in the PI futexes during fault handling, allowing local users to execute code in the kernel (bsc#1181553). - CVE-2020-27786: Fixed a potential user after free which could have led to memory corruption or privilege escalation (bsc#1179616). - CVE-2020-28374: Fixed insufficient identifier checking in the LIO SCSI target code which could have been used by remote attackers to read or write files via directory traversal in an XCOPY request (bsc#1178684).