Security update for xen

Open Source Vulnerabilities SUSE-SU-2019:14201-1

This update for xen fixes the following issues: - CVE-2019-15890: Fixed a use-after-free in SLiRP networking implementation of QEMU emulator which could have led to Denial of Service (bsc#1149813). - CVE-2019-12068: Fixed an issue in lsi which could lead to an infinite loop and denial of service (bsc#1146874). - CVE-2019-14378: Fixed a heap buffer overflow in SLiRp networking implementation of QEMU emulator which could have led to execution of arbitrary code with privileges of the QEMU process (bsc#1143797). - CVE-2019-12067: Fixed a null pointer dereference which could have led to denial of service (bsc#1145652). - CVE-2019-12155: Fixed a null pointer dereference in QXL VGA card emulator of QEMU which could have led to denial of service (bsc#1135905). - CVE-2018-20815: Fixed a heap buffer overflow while loading device tree blob (bsc#1130680). - CVE-2017-10806: Fixed a stack buffer overflow in debug logging (bsc#1047675).