FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

xen-kernel -- leak of main per-domain vcpu pointer array

Affected packages
xen-kernel < 4.5.1_1


VuXML ID fc1f8795-881d-11e5-ab94-002590263bf5
Discovery 2015-10-29
Entry 2015-11-11

The Xen Project reports:

A domain's primary array of vcpu pointers can be allocated by a toolstack exactly once in the lifetime of a domain via the XEN_DOMCTL_max_vcpus hypercall. This array is leaked on domain teardown. This memory leak could -- over time -- exhaust the host's memory.

A domain given partial management control via XEN_DOMCTL_max_vcpus can mount a denial of service attack affecting the whole system. 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. The maximum leak is 64kbytes per domain (re)boot (less on ARM).


CVE Name CVE-2015-7969