The current read/write lock implementation is read-biased, which allows a consistent stream of readers to starve writers indefinitely. There are certain rwlocks where guests are capable of applying arbitrary read pressure. A malicious guest administrator can deny service to other tasks. If the NMI watchdog is active, a timeout might be triggered, resulting in a host 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.