CVE-2021-47450
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2021-47450
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47450.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2021-47450
- Downstream
- Related
- Published
- 2024-05-22T07:15:10Z
- Modified
- 2025-09-24T01:07:53Z
- Severity
-
- 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Fix host stage-2 PGD refcount
The KVM page-table library refcounts the pages of concatenated stage-2 PGDs individually. However, when running KVM in protected mode, the host's stage-2 PGD is currently managed by EL2 as a single high-order compound page, which can cause the refcount of the tail pages to reach 0 when they shouldn't, hence corrupting the page-table.
Fix this by introducing a new hypsplitpage() helper in the EL2 page allocator (matching the kernel's splitpage() function), and make use of it from hosts2zallocpages_exact().
- References