CVEvulnerability

CVE-2021-47450

5.5 MEDIUM Published 2024-05-22 Modified 2026-08-04 Official page ↗
Status
Modified
Published
2024-05-22
Last modified
2026-08-04
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
8.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS 3.1 ([email protected])
5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Description

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 hyp_split_page() helper in the EL2 page allocator (matching the kernel's split_page() function), and make use of it from host_s2_zalloc_pages_exact().

Affected configurations

• linux linux kernel (>= 5.13 < 5.14.15) • linux linux kernel 5.15

References