A PV guest could DoS Xen while unmapping a grant To...
Moderate severity
Unreviewed
Published
Jan 26, 2022
to the GitHub Advisory Database
•
Updated Jan 27, 2023
Description
Published by the National Vulnerability Database
Jan 25, 2022
Published to the GitHub Advisory Database
Jan 26, 2022
Last updated
Jan 27, 2023
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.
References