xen-kernel -- leak of per-domain profiling-related vcpu pointer array

The Xen Project reports:

A domain’s xenoprofile state contains an array of per-vcpu
information… This array is leaked on domain teardown. This memory
leak could – over time – exhaust the host’s memory.
The following parties can mount a denial of service attack
affecting the whole system:

A malicious guest administrator via XENOPROF_get_buffer.
A domain given suitable privilege over another domain via
XENOPROF_set_passive (this would usually be a domain being
used to profile another domain, eg with the xenoprof tool).

The ability to also restart or create suitable domains is also
required to fully exploit the issue. Without this the leak is
limited to a small multiple of the maximum number of vcpus for the
domain.