The PHYSDEVOP_{prepare,release}_msix operations are supposed to be available to privileged guests (domain 0 in non-disaggregated setups) only, but the necessary privilege check was missing.
Malicious or misbehaving unprivileged guests can cause the host or other guests to malfunction. This can result in host-wide denial of service. Privilege escalation, while seeming to be unlikely, cannot be excluded.
References:
http://seclists.org/oss-sec/2014/q1/150
Acknowledgements:
Red Hat would like to thank the Xen project for reporting this issue.
Statement:
Not vulnerable.
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 2 as we did not have support for Xen hypervisor.
The PHYSDEVOP_{prepare,release}_msix operations are supposed to be available to privileged guests (domain 0 in non-disaggregated setups) only, but the necessary privilege check was missing. Malicious or misbehaving unprivileged guests can cause the host or other guests to malfunction. This can result in host-wide denial of service. Privilege escalation, while seeming to be unlikely, cannot be excluded. References: http://seclists.org/oss-sec/2014/q1/150 Acknowledgements: Red Hat would like to thank the Xen project for reporting this issue.