This update for xen fixes several issues.
These security issues were fixed:
- CVE-2017-5753, CVE-2017-5715, CVE-2017-5754: Prevent information leaks
via side effects of speculative execution, aka "Spectre" and "Meltdown"
attacks (bsc#1074562, bsc#1068032)
- CVE-2018-5683: The vga_draw_text function allowed local OS guest
privileged users to cause a denial of service (out-of-bounds read and
QEMU process crash) by leveraging improper memory address validation
(bsc#1076116).
- CVE-2017-18030: The cirrus_invalidate_region function allowed local OS
guest privileged users to cause a denial of service (out-of-bounds array
access and QEMU process crash) via vectors related to negative pitch
(bsc#1076180).
- CVE-2017-15595: x86 PV guest OS users were able to cause a DoS
(unbounded recursion, stack consumption, and hypervisor crash) or
possibly gain privileges via crafted page-table stacking (bsc#1061081)
- CVE-2017-17566: Prevent PV guest OS users to cause a denial of service
(host OS crash) or gain host OS privileges in shadow mode by mapping a
certain auxiliary page (bsc#1070158).
- CVE-2017-17563: Prevent guest OS users to cause a denial of service
(host OS crash) or gain host OS privileges by leveraging an incorrect
mask for reference-count overflow checking in shadow mode (bsc#1070159).
- CVE-2017-17564: Prevent guest OS users to cause a denial of service
(host OS crash) or gain host OS privileges by leveraging incorrect error
handling for reference counting in shadow mode (bsc#1070160).
- CVE-2017-17565: Prevent PV guest OS users to cause a denial of service
(host OS crash) if shadow mode and log-dirty mode are in place, because
of an incorrect assertion related to M2P (bsc#1070163).
- Added missing intermediate preemption checks for guest requesting
removal of memory. This allowed malicious guest administrator to cause
denial of service due to the high cost of this operation (bsc#1080635).
- Because of XEN not returning the proper error messages when
transitioning grant tables from v2 to v1 a malicious guest was able to
cause DoS or potentially allowed for privilege escalation as well as
information leaks (bsc#1080662).
- CVE-2017-5898: The CCID Card device emulator support was vulnerable to
an integer overflow flaw allowing a privileged user to crash the Qemu
process on the host resulting in DoS (bsc#1024307)
- Unprivileged domains could have issued well-timed writes to xenstore
which conflict with transactions to stall progress of the control domain
or driver domain, possibly leading to DoS (bsc#1030144, XSA-206).