XENMEM_populate_physmap can be called with invalid flags. By calling it with MEMF_populate_on_demand flag set, a BUG can be triggered if a translating paging mode is not being used.
A malicious guest kernel can crash the host.
Red Hat would like to thank the Xen project for reporting this issue. Upstream acknowledges Matthew Daley as the original reporter.
This issue did not affect the versions of the kernel-xen package as shipped with Red Hat Enterprise Linux 5.
This issue did not affect Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG as we did not have support for Xen hypervisor.
Now public via:
Created xen tracking bugs for this issue
Affects: fedora-all [bug 854590]
xen-4.1.3-2.fc16 has been pushed to the Fedora 16 stable repository. If problems still persist, please make note of it in this bug report.