When passing a device which is behind a legacy PCI Bridge through to a guest Xen incorrectly configures the VT-d hardware. This could allow incorrect interrupts to be injected to other guests which also have passthrough devices. In a typical Xen system many devices are owned by domain 0 or driver domains, leaving them vulnerable to such an attack. Such a DoS is likely to have an impact on other guests running in the system. On systems using Intel VT-d for PCI passthrough a malicious domain, given access to a device which is behind a legacy PCI bridge, can mount a denial of service attack affecting the whole system. 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 as we did not have support for Xen hypervisor.
Created xen tracking bugs for this issue Affects: fedora-all [bug 893568]
xen-4.1.4-2.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.
xen-4.2.1-3.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.
xen-4.1.4-3.fc16 has been pushed to the Fedora 16 stable repository. If problems still persist, please make note of it in this bug report.