GHSA-JG4Q-H984-9PJC
Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-09-04 15:35In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - Do not initialize SNP for ioctl(SNP_VLEK_LOAD)
Sashiko notes:
if SEV initialization fails and KVM is actively running normal VMs, could a userspace process trigger this code path via /dev/sev ioctls (e.g., SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN execution for an active VM trigger a general protection fault and crash the host?
The SEV firmware docs for SNP_VLEK_LOAD note:
On SNP_SHUTDOWN, the VLEK is deleted.
That is, the initialization/shutdown wrapper here is pointless, because the firmware immediately throws away the key anyway. Instead, refuse to do anything if SNP has not been previously initialized.
This is an ABI break: before, this was a no-op and almost certainly a mistake by userspace, and now it returns -ENODEV. ABI compatibility could be maintained here by simply returning 0 in the check instead.
{
"affected": [],
"aliases": [
"CVE-2026-64308"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-25T10:17:11Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Do not initialize SNP for ioctl(SNP_VLEK_LOAD)\n\nSashiko notes:\n\n\u003e if SEV initialization fails and KVM is actively running normal VMs, could a\n\u003e userspace process trigger this code path via /dev/sev ioctls (e.g.,\n\u003e SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN\n\u003e execution for an active VM trigger a general protection fault and crash the\n\u003e host?\n\nThe SEV firmware docs for SNP_VLEK_LOAD note:\n\n\u003e On SNP_SHUTDOWN, the VLEK is deleted.\n\nThat is, the initialization/shutdown wrapper here is pointless, because the\nfirmware immediately throws away the key anyway. Instead, refuse to do\nanything if SNP has not been previously initialized.\n\nThis is an ABI break: before, this was a no-op and almost certainly a\nmistake by userspace, and now it returns -ENODEV. ABI compatibility could be\nmaintained here by simply returning 0 in the check instead.",
"id": "GHSA-jg4q-h984-9pjc",
"modified": "2026-09-04T15:35:49Z",
"published": "2026-07-25T12:31:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64308"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/61cf5eef20657bff9ca235fe938a99ce5ff65c06"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8836801847b9479ac046cb18a24981e1b0b05e9d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/92567ed9306d5a3d1b007eb4faeff30cc3ffc3e4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f91e9dbb5845d1e5abf1028e6df57dcf61583e1b"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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