Security update for xen

Open Source Vulnerabilities SUSE-SU-2022:3728-1

This update for xen fixes the following issues: - CVE-2022-26365: Fixed issue where Linux Block and Network PV device frontends don't zero memory regions before sharing them with the backend (bsc#1200762). - CVE-2022-33740: Fixed issue where Linux Block and Network PV device frontends don't zero memory regions before sharing them with the backend (bsc#1200762). - CVE-2022-33741: Fixed issue where data residing in the same 4K page as data shared with a backend was being accessible by such backend (bsc#1200762). - CVE-2022-33742: Fixed issue where data residing in the same 4K page as data shared with a backend was being accessible by such backend (bsc#1200762). - CVE-2022-33746: Fixed DoS due to excessively long P2M pool freeing (bsc#1203806). - CVE-2021-28689: Fixed speculative vulnerabilities with bare (non-shim) 32-bit PV guests (bsc#1185104). - CVE-2022-33748: Fixed DoS due to race in locking (bsc#1203807).