xen-tools -- Unsanitised guest input in libxl device handling code

The Xen Project reports:

Various parts of libxl device-handling code inappropriately use
information from (partially) guest controlled areas of xenstore.
A malicious guest administrator can cause denial of service by
resource exhaustion.
A malicious guest administrator can confuse and/or deny service to
management facilities.
A malicious guest administrator of a guest configured with channel
devices may be able to escalate their privilege to that of the
backend domain (i.e., normally, to that of the host).