Security update for xen

Open Source Vulnerabilities SUSE-SU-2020:1630-1

This update for xen fixes the following issues: - CVE-2020-0543: Fixed a side channel attack against special registers which could have resulted in leaking of read values to cores other than the one which called it. This attack is known as Special Register Buffer Data Sampling (SRBDS) or 'CrossTalk' (bsc#1172205). - CVE-2020-11742: Bad continuation handling in GNTTABOP_copy (bsc#1169392). - CVE-2020-11740, CVE-2020-11741: xen: XSA-313 multiple xenoprof issues (bsc#1168140). - CVE-2020-11739: Missing memory barriers in read-write unlock paths (bsc#1168142). - CVE-2019-19583: Fixed improper checks which could have allowed HVM/PVH guest userspace code to crash the guest, leading to a guest denial of service (bsc#1158004 XSA-308). - CVE-2019-19581: Fixed a potential out of bounds on 32-bit Arm (bsc#1158003 XSA-307). - CVE-2019-19580: Fixed a privilege escalation where a malicious PV guest administrator could have been able to escalate their privilege to that of the host (bsc#1158006 XSA-310). - CVE-2019-19579: Fixed a privilege escalation where an untrusted domain with access to a physical device can DMA into host memory (bsc#1157888 XSA-306). - CVE-2019-19578: Fixed an issue where a malicious or buggy PV guest could have caused hypervisor crash resulting in denial of service affecting the entire host (bsc#1158005 XSA-309). - CVE-2019-19577: Fixed an issue where a malicious guest administrator could have caused Xen to access data structures while they are being modified leading to a crash (bsc#1158007 XSA-311). - Xenstored Crashed during VM install (bsc#1167152)