PT-2021-8191 · Linux+3 · Linux Kernel+3
Published
2021-10-05
·
Updated
2025-09-24
·
CVE-2021-47450
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The issue is related to the KVM page-table library refcounting 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. This can be fixed by introducing a new
hyp split page() helper in the EL2 page allocator and making use of it from host s2 zalloc pages exact(). The vulnerability may allow an attacker to cause a denial of service.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
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Weakness Enumeration
Related Identifiers
Affected Products
Astra Linux
Linux Kernel
Red Os
Suse