Various IRQ related access control operations may not have the intended effect, thus potentially permitting a stub domain to gran its client domain access to an IRQ it doesn't have access to itself. Malicious or buggy stub domains kernels can mount a denial of service attack possibly affecting the whole system. Only Xen systems using stub domains are vulnerable. Only HVM guests with passed-through IRQs or PCI devices are able to exploit the vulnerability. Acknowledgements: Red Hat would like to thank the Xen 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 as it has no support for stub domains. This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6 and Red Hat Enterprise MRG as we did not have support for Xen hypervisor.
Created xen tracking bugs for this issue Affects: fedora-all [bug 953568]
xen-4.1.5-1.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.
xen-4.2.2-1.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.