Allocation of pages used to communicate with external emulators did not
follow certain principles that are required for proper life cycle
management of guest exposed pages.
A compromised DM stubdomain may cause Xen to crash, resulting in a DoS
(Denial of Service) affecting the entire host. Privilege escalation
as well as information leaks cannot be ruled out.
Only Xen 4.11 is affected by this vulnerability. Xen 4.10 and older are
not affected by this vulnerability.
Only systems running HVM guests with their devicemodels in a
stubdomain are considered vulnerable. Note that attackers also need
to exploit the devicemodel in order to have access to this
Arm guests cannot leverage this vulnerability.
Running only PV guests will avoid this vulnerability.
(The security of a Xen system using stub domains is still better than
with a qemu-dm running as an unrestricted dom0 process. Therefore
users with these configurations should not switch to an unrestricted
Name: the Xen project
Upstream: Julien Grall (ARM)
Created xen tracking bugs for this issue:
Affects: fedora-all [bug 1652251]