Security update for xen

Open Source Vulnerabilities SUSE-SU-2019:0891-1

This update for xen fixes the following issues: Security issues fixed: - Fixed an issue which could allow malicious PV guests may cause a host crash or gain access to data pertaining to other guests.Additionally, vulnerable configurations are likely to be unstable even in the absence of an attack (bsc#1126198). - Fixed multiple access violations introduced by XENMEM_exchange hypercall which could allow a single PV guest to leak arbitrary amounts of memory, leading to a denial of service (bsc#1126192). - Fixed an issue which could allow a malicious unprivileged guest userspace process to escalate its privilege to that of other userspace processes in the same guest and potentially thereby to that of the guest operating system (bsc#1126201). - Fixed an issue which could allow malicious or buggy x86 PV guest kernels to mount a Denial of Service attack affecting the whole system (bsc#1126197). - Fixed an issue which could allow an untrusted PV domain with access to a physical device to DMA into its own pagetables leading to privilege escalation (bsc#1126195). - Fixed an issue which could allow a malicious or buggy x86 PV guest kernels can mount a Denial of Service attack affecting the whole system (bsc#1126196). - CVE-2019-6778: Fixed a heap buffer overflow in tcp_emu() found in slirp (bsc#1123157). - Fixed an issue which could allow malicious 64bit PV guests to cause a host crash (bsc#1127400). - Fixed an issue which could allow malicious or buggy guests with passed through PCI devices to be able to escalate their privileges, crash the host, or access data belonging to other guests. Additionally memory leaks were also possible (bsc#1126140). - Fixed a race condition issue which could allow malicious PV guests to escalate their privilege to that of the hypervisor (bsc#1126141). - CVE-2019-9824: Fixed an information leak in SLiRP networking implementation which could allow a user/process to read uninitialised stack memory contents (bsc#1129623). Other issues addressed: - Upstream bug fixes (bsc#1027519) - Packages should no longer use /var/adm/fillup-templates (bsc#1069468). - Added Xen cmdline option 'suse_vtsc_tolerance' to avoid TSC emulation for HVM domUs (bsc#1026236). - Fixed an issue where setup of grant_tables and other variables may fail (bsc#1126325). - Fixed a building issue (bsc#1119161). - Added a requirement for xen, xl.cfg firmware='pvgrub32|pvgrub64 (bsc#1127620). - Fixed a segmetation fault in Libvirt when crash triggered on top of HVM guest (bsc#1120067).