CVE-2021-28701

Another race in XENMAPSPACEgranttable 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.

References

Affected packages

Git /

Affected ranges

Database specific

unresolved_ranges

[
    {
        "events": [
            {
                "introduced": "4.0.0"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "last_affected": "11.0"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "last_affected": "33"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "last_affected": "34"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "last_affected": "35"
            }
        ]
    }
]

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-28701.json"