Processors do certain validity checks on the data passed to XRSTOR. While the hypervisor controls the placement of that memory block, it doesn't restrict the contents in any way. Thus the hypervisor exposes itself to a fault occurring on XRSTOR. Other than for FXRSTOR, which behaves similarly, there was no exception recovery code attached to XRSTOR. Malicious or buggy unprivileged user space can cause the entire host to crash. 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.
Now public via: http://www.openwall.com/lists/oss-security/2013/06/03/2
Created xen tracking bugs for this issue Affects: fedora-all [bug 970204]
xen-4.2.2-6.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.
xen-4.2.2-6.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.
xen-4.1.5-5.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.