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.
Metrics
Affected Vendors & Products
Advisories
Source | ID | Title |
---|---|---|
![]() |
DSA-4977-1 | xen security update |
![]() |
EUVD-2021-15358 | 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. |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
No history.

Status: PUBLISHED
Assigner: XEN
Published:
Updated: 2024-08-03T21:47:33.200Z
Reserved: 2021-03-18T00:00:00
Link: CVE-2021-28701

No data.

Status : Modified
Published: 2021-09-08T14:15:08.547
Modified: 2024-11-21T06:00:10.450
Link: CVE-2021-28701

No data.

No data.