description: Another race in XENMAPSPACE_grant_table handling Guests are permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, are de-allocated when a guest switches (back) from v2 to v1. Freeing such pages requires that the hypervisor enforce that no parallel request can result in the addition of a mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared, this similar issue was not noticed.
problem types: unknown
affected:
{
product: xen
vendor: Xen
versions:
lessThan: 4.12, status: unknown, version: unspecified, versionType: custom
lessThan: unspecified, status: affected, version: 4.15.x, versionType: custom
lessThan: unspecified, status: unaffected, version: next of xen-unstable, versionType: custom
}
{
product: xen
vendor: Xen
versions:
status: affected, version: 4.11.x
}
{
product: xen
vendor: Xen
versions:
lessThan: 4.12, status: unknown, version: unspecified, versionType: custom
lessThan: unspecified, status: affected, version: 4.12.x, versionType: custom
lessThan: unspecified, status: unaffected, version: next of 4.14.x, versionType: custom
}
metrics:
other: [
content: {'description': {'description_data': [{'lang': 'eng', 'value': 'A malicious guest may be able to elevate its privileges to that of the\nhost, cause host or guest Denial of Service (DoS), or cause information\nleaks.'}]}}
type: unknown
]