CVE-2021-28701 (GCVE-0-2021-28701)
Vulnerability from cvelistv5
Published
2021-09-08 13:02
Modified
2024-08-03 21:47
Severity ?
CWE
  • unknown
Summary
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.
References
Impacted products
Vendor Product Version
Xen xen Version: 4.15.x   < unspecified
Patch: next of xen-unstable   < unspecified
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   Xen xen Version: 4.11.x
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   Xen xen Version: 4.12.x   < unspecified
Patch: next of 4.14.x   < unspecified
 Create a notification for this product.
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