CVE-2021-47450
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
22/05/2024
Last modified:
24/09/2025
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
KVM: arm64: Fix host stage-2 PGD refcount<br />
<br />
The KVM page-table library refcounts the pages of concatenated stage-2<br />
PGDs individually. However, when running KVM in protected mode, the<br />
host&#39;s stage-2 PGD is currently managed by EL2 as a single high-order<br />
compound page, which can cause the refcount of the tail pages to reach 0<br />
when they shouldn&#39;t, hence corrupting the page-table.<br />
<br />
Fix this by introducing a new hyp_split_page() helper in the EL2 page<br />
allocator (matching the kernel&#39;s split_page() function), and make use of<br />
it from host_s2_zalloc_pages_exact().
Impact
Base Score 3.x
5.50
Severity 3.x
MEDIUM
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.13 (including) | 5.14.15 (excluding) |
| cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:* | ||
| cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:* |
To consult the complete list of CPE names with products and versions, see this page