GHSA-5GVM-8X7G-H7XX
Vulnerability from github – Published: 2026-04-24 15:32 – Updated: 2026-04-24 15:32In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Drop WARN on large size for KVM_MEMORY_ENCRYPT_REG_REGION
Drop the WARN in sev_pin_memory() on npages overflowing an int, as the WARN is comically trivially to trigger from userspace, e.g. by doing:
struct kvm_enc_region range = { .addr = 0, .size = -1ul, };
__vm_ioctl(vm, KVM_MEMORY_ENCRYPT_REG_REGION, &range);
Note, the checks in sev_mem_enc_register_region() that presumably exist to verify the incoming address+size are completely worthless, as both "addr" and "size" are u64s and SEV is 64-bit only, i.e. they can't be greater than ULONG_MAX. That wart will be cleaned up in the near future.
if (range->addr > ULONG_MAX || range->size > ULONG_MAX)
return -EINVAL;
Opportunistically add a comment to explain why the code calculates the number of pages the "hard" way, e.g. instead of just shifting @ulen.
{
"affected": [],
"aliases": [
"CVE-2026-31590"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-24T15:16:36Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Drop WARN on large size for KVM_MEMORY_ENCRYPT_REG_REGION\n\nDrop the WARN in sev_pin_memory() on npages overflowing an int, as the\nWARN is comically trivially to trigger from userspace, e.g. by doing:\n\n struct kvm_enc_region range = {\n .addr = 0,\n .size = -1ul,\n };\n\n __vm_ioctl(vm, KVM_MEMORY_ENCRYPT_REG_REGION, \u0026range);\n\nNote, the checks in sev_mem_enc_register_region() that presumably exist to\nverify the incoming address+size are completely worthless, as both \"addr\"\nand \"size\" are u64s and SEV is 64-bit only, i.e. they _can\u0027t_ be greater\nthan ULONG_MAX. That wart will be cleaned up in the near future.\n\n\tif (range-\u003eaddr \u003e ULONG_MAX || range-\u003esize \u003e ULONG_MAX)\n\t\treturn -EINVAL;\n\nOpportunistically add a comment to explain why the code calculates the\nnumber of pages the \"hard\" way, e.g. instead of just shifting @ulen.",
"id": "GHSA-5gvm-8x7g-h7xx",
"modified": "2026-04-24T15:32:34Z",
"published": "2026-04-24T15:32:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31590"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1cba4dcd795daf6d257122779fb6a349edf03914"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/28cc13ca20431b127d42d84ba10898d03e2c8267"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ab423e5892826202a660b5ac85d1125b0e8301a5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c29ff288a2d97a6f4640a498a367cf0eb91312eb"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.