KVM: arm64: Fix host stage-2 PGD refcount (Linux Linux)

CVE-2021-47450
HIGH 8.8

At a glance

Source
NVD
EPSS
EPSS 0.21 % · percentile 11 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

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().

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HLinux
CVSS 3.1HIGH 8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HNVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary)
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 1025c8c0c6accfcbdc8f52ca1940160f65cd87d6 < b372264c66ef78f2cab44e877fbd765ad6d24c39 ; affected 1025c8c0c6accfcbdc8f52ca1940160f65cd87d6 < 1d58a17ef54599506d44c45ac95be27273a4d2b1
Linux · Linuxaffected 5.13 ; unaffected 0 < 5.13 ; unaffected 5.14.15 ≤ 5.14.* ; unaffected 5.15 ≤ *

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD