PHYSDEVOP_map_pirq with MAP_PIRQ_TYPE_GSI does not range check map->index.
A malicious HVM guest kernel can crash the host. It might also be able to read hypervisor or guest memory.
All Xen systems running HVM guests are vulnerable. PV guests are not vulnerable.
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 854593]
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.