KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer (Linux Linux)

CVE-2026-63937
HIGH 8.8

At a glance

Source
NVD
EPSS
EPSS 0.14 % · percentile 3 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer Use READ_ONCE() when reading entries/indices from the guest-accessible Page State Change buffer to defend against TOCTOU bugs. Don't bother with READ_ONCE()/WRITE_ONCE() for cases where KVM is writing (and not consuming the result!), as the guest isn't supposed to touch the buffer while it's being processed. I.e. using READ_ONCE() is all about protecting against misbehaving guests.

Weaknesses (CWE)

  • CWE-367 — Time-of-check Time-of-use (TOCTOU) Race Condition

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)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 9b54e248d2644be71cb394eb85f31ad99e023a05 < bd232801ef1d1fd985d2d4ca3cd1d888303ca86f ; affected 9b54e248d2644be71cb394eb85f31ad99e023a05 < b1dfaa6f7a957726a6800135be3659fbe4bbf2a4 ; affected 9b54e248d2644be71cb394eb85f31ad99e023a05 < edbbe88f83b524434974e84808d3093199d67c24 ; affected 9b54e248d2644be71cb394eb85f31ad99e023a05 < c8cc238093ca6c99267032f6cfe78f59389f3157
Linux · Linuxaffected 6.11 ; unaffected 0 < 6.11 ; unaffected 6.12.93 ≤ 6.12.* ; unaffected 6.18.35 ≤ 6.18.* ; unaffected 7.0.12 ≤ 7.0.* ; unaffected 7.1 ≤ *

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