CVE-2026-31590 (GCVE-0-2026-31590)

Vulnerability from cvelistv5 – Published: 2026-04-24 14:42 – Updated: 2026-04-24 14:42
VLAI?
Title
KVM: SEV: Drop WARN on large size for KVM_MEMORY_ENCRYPT_REG_REGION
Summary
In 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.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < ab423e5892826202a660b5ac85d1125b0e8301a5 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 28cc13ca20431b127d42d84ba10898d03e2c8267 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c29ff288a2d97a6f4640a498a367cf0eb91312eb (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 1cba4dcd795daf6d257122779fb6a349edf03914 (git)
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    Linux Linux Unaffected: 6.12.83 , ≤ 6.12.* (semver)
Unaffected: 6.18.24 , ≤ 6.18.* (semver)
Unaffected: 6.19.14 , ≤ 6.19.* (semver)
Unaffected: 7.0.1 , ≤ 7.0.* (semver)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/sev.c"
          ],
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          "vendor": "Linux",
          "versions": [
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              "status": "unaffected",
              "version": "6.12.83",
              "versionType": "semver"
            },
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              "versionType": "semver"
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              "versionType": "semver"
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              "status": "unaffected",
              "version": "7.0.1",
              "versionType": "semver"
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      "cpeApplicability": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-24T14:42:17.629Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/ab423e5892826202a660b5ac85d1125b0e8301a5"
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        {
          "url": "https://git.kernel.org/stable/c/c29ff288a2d97a6f4640a498a367cf0eb91312eb"
        },
        {
          "url": "https://git.kernel.org/stable/c/1cba4dcd795daf6d257122779fb6a349edf03914"
        }
      ],
      "title": "KVM: SEV: Drop WARN on large size for KVM_MEMORY_ENCRYPT_REG_REGION",
      "x_generator": {
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  },
  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31590",
    "datePublished": "2026-04-24T14:42:17.629Z",
    "dateReserved": "2026-03-09T15:48:24.120Z",
    "dateUpdated": "2026-04-24T14:42:17.629Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-31590",
      "date": "2026-04-26",
      "epss": "0.00018",
      "percentile": "0.0462"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-31590\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-04-24T15:16:36.170\",\"lastModified\":\"2026-04-24T17:51:40.810\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"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.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/1cba4dcd795daf6d257122779fb6a349edf03914\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/28cc13ca20431b127d42d84ba10898d03e2c8267\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ab423e5892826202a660b5ac85d1125b0e8301a5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c29ff288a2d97a6f4640a498a367cf0eb91312eb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • 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.



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