description: A PV guest could DoS Xen while unmapping a grant To address XSA-380, reference counting was introduced for grant mappings for the case where a PV guest would have the IOMMU enabled. PV guests can request two forms of mappings. When both are in use for any individual mapping, unmapping of such a mapping can be requested in two steps. The reference count for such a mapping would then mistakenly be decremented twice. Underflow of the counters gets detected, resulting in the triggering of a hypervisor bug check.
problem types: unknown
affected:
{
product: xen
vendor: Xen
versions:
status: unknown, version: consult Xen advisory XSA-394
}
metrics:
other: [
content: {'description': {'description_data': [{'lang': 'eng', 'value': 'Malicious guest kernels may be able to mount a Denial of Service (DoS)\nattack affecting the entire system.'}]}}
type: unknown
]