KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer
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.
CVE-2026-63937
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-63937
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "9b54e248d2644be71cb394eb85f31ad99e023a05",
"lessThan": "bd232801ef1d1fd985d2d4ca3cd1d888303ca86f",
"versionType": "git"
},
{
"status": "affected",
"version": "9b54e248d2644be71cb394eb85f31ad99e023a05",
"lessThan": "b1dfaa6f7a957726a6800135be3659fbe4bbf2a4",
"versionType": "git"
},
{
"status": "affected",
"version": "9b54e248d2644be71cb394eb85f31ad99e023a05",
"lessThan": "edbbe88f83b524434974e84808d3093199d67c24",
"versionType": "git"
},
{
"status": "affected",
"version": "9b54e248d2644be71cb394eb85f31ad99e023a05",
"lessThan": "c8cc238093ca6c99267032f6cfe78f59389f3157",
"versionType": "git"
}
],
"programFiles": [
"arch/x86/kvm/svm/sev.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.35",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.12",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/kvm/svm/sev.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-63937
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40900 · Revision 1
- Added to Heist Feed
- Publisher date