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
| Link | Resource |
|---|---|
| https://xenbits.xenproject.org/xsa/advisory-384.txt | Vendor Advisory |
| http://xenbits.xen.org/xsa/advisory-384.html | Vendor Advisory |
| http://www.openwall.com/lists/oss-security/2021/09/08/2 | Mailing List Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/L4MI3MQAPGILCLXBGQWPZHGE3ALSO4ZU/ | Mailing List Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CEHZLIR5DFYYQBH55AERWHLO54OFU42C/ | Mailing List Third Party Advisory |
| https://www.debian.org/security/2021/dsa-4977 | Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3HEHUIUWSSMCQGQY3GWX4J2SZGYP5W2Z/ | Mailing List Third Party Advisory |
| https://security.gentoo.org/glsa/202208-23 | Third Party Advisory |
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Configurations
Information
Published : 2021-09-08 07:15
Updated : 2022-10-28 09:20
NVD link : CVE-2021-28701
Mitre link : CVE-2021-28701
JSON object : View
CWE
CWE-362
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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Products Affected
debian
- debian_linux
xen
- xen
fedoraproject
- fedora