vulnerability
Gentoo Linux: CVE-2021-28701: Xen: Multiple Vulnerabilities
Severity | CVSS | Published | Added | Modified |
---|---|---|---|---|
7 | (AV:L/AC:M/Au:S/C:C/I:C/A:C) | 2021-09-08 | 2022-08-16 | 2025-01-28 |
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.
Solution(s)

Explore Exposure Command
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