Vulnerability-Lookup

CVE-2026-43348 (GCVE-0-2026-43348)

Vulnerability from cvelistv5 – Published: 2026-05-08 13:41 – Updated: 2026-05-08 13:41

Title

mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER

Summary

In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and last_pfn, intending to use the largest compound page order both endpoints are aligned to. However, this value is not clamped to MAX_FOLIO_ORDER, so a sufficiently aligned range (e.g. physical range [0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000 with 35 trailing zeros) can produce a shift larger than what memremap_pages() accepts, triggering a WARN and returning -EINVAL: WARNING: ... memremap_pages+0x512/0x650 requested folio size unsupported The MAX_FOLIO_ORDER check was added by commit 646b67d57589 ("mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages()"). Fix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always request the largest order the kernel supports, in those cases, rather than an out-of-range value. Also fix the error path to propagate the actual error code from devm_memremap_pages() instead of hard-coding -EFAULT, which was masking the real -EINVAL return.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/a142ca4b6481e7149…
	https://git.kernel.org/stable/c/404cd6bffe17e25e0…

Impacted products

Vendor

Product

Version

Linux

Affected: 7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f , < a142ca4b6481e71498712800b20e0c0fcf02843b (git)
Affected: 7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f , < 404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd (git)

Linux

Affected: 6.19
Unaffected: 0 , < 6.19 (semver)
Unaffected: 7.0.2 , ≤ 7.0.* (semver)
Unaffected: 7.1-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hv/mshv_vtl_main.c",
            "include/uapi/linux/mshv.h"
          ],
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          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a142ca4b6481e71498712800b20e0c0fcf02843b",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f",
              "versionType": "git"
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              "version": "6.19"
            },
            {
              "lessThan": "6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1-rc1",
              "versionType": "original_commit_for_fix"
            }
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        }
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      "cpeApplicability": [
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          "nodes": [
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                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                },
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER\n\nWhen registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel\ncomputes pgmap-\u003evmemmap_shift as the number of trailing zeros in the\nOR of start_pfn and last_pfn, intending to use the largest compound\npage order both endpoints are aligned to.\n\nHowever, this value is not clamped to MAX_FOLIO_ORDER, so a\nsufficiently aligned range (e.g. physical range\n[0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000\nwith 35 trailing zeros) can produce a shift larger than what\nmemremap_pages() accepts, triggering a WARN and returning -EINVAL:\n\n  WARNING: ... memremap_pages+0x512/0x650\n  requested folio size unsupported\n\nThe MAX_FOLIO_ORDER check was added by\ncommit 646b67d57589 (\"mm/memremap: reject unreasonable folio/compound\npage sizes in memremap_pages()\").\n\nFix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always\nrequest the largest order the kernel supports, in those cases, rather\nthan an out-of-range value.\n\nAlso fix the error path to propagate the actual error code from\ndevm_memremap_pages() instead of hard-coding -EFAULT, which was\nmasking the real -EINVAL return."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-08T13:41:51.909Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/a142ca4b6481e71498712800b20e0c0fcf02843b"
        },
        {
          "url": "https://git.kernel.org/stable/c/404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd"
        }
      ],
      "title": "mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER",
      "x_generator": {
        "engine": "bippy-1.2.0"
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43348",
    "datePublished": "2026-05-08T13:41:51.909Z",
    "dateReserved": "2026-05-01T14:12:56.003Z",
    "dateUpdated": "2026-05-08T13:41:51.909Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-43348",
      "date": "2026-05-09",
      "epss": "0.00018",
      "percentile": "0.05073"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-43348\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-05-08T14:16:44.890\",\"lastModified\":\"2026-05-08T14:16:44.890\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER\\n\\nWhen registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel\\ncomputes pgmap-\u003evmemmap_shift as the number of trailing zeros in the\\nOR of start_pfn and last_pfn, intending to use the largest compound\\npage order both endpoints are aligned to.\\n\\nHowever, this value is not clamped to MAX_FOLIO_ORDER, so a\\nsufficiently aligned range (e.g. physical range\\n[0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000\\nwith 35 trailing zeros) can produce a shift larger than what\\nmemremap_pages() accepts, triggering a WARN and returning -EINVAL:\\n\\n  WARNING: ... memremap_pages+0x512/0x650\\n  requested folio size unsupported\\n\\nThe MAX_FOLIO_ORDER check was added by\\ncommit 646b67d57589 (\\\"mm/memremap: reject unreasonable folio/compound\\npage sizes in memremap_pages()\\\").\\n\\nFix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always\\nrequest the largest order the kernel supports, in those cases, rather\\nthan an out-of-range value.\\n\\nAlso fix the error path to propagate the actual error code from\\ndevm_memremap_pages() instead of hard-coding -EFAULT, which was\\nmasking the real -EINVAL return.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a142ca4b6481e71498712800b20e0c0fcf02843b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}

FKIE_CVE-2026-43348

Vulnerability from fkie_nvd - Published: 2026-05-08 14:16 - Updated: 2026-05-08 14:16

Severity ?

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a142ca4b6481e71498712800b20e0c0fcf02843b

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER\n\nWhen registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel\ncomputes pgmap-\u003evmemmap_shift as the number of trailing zeros in the\nOR of start_pfn and last_pfn, intending to use the largest compound\npage order both endpoints are aligned to.\n\nHowever, this value is not clamped to MAX_FOLIO_ORDER, so a\nsufficiently aligned range (e.g. physical range\n[0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000\nwith 35 trailing zeros) can produce a shift larger than what\nmemremap_pages() accepts, triggering a WARN and returning -EINVAL:\n\n  WARNING: ... memremap_pages+0x512/0x650\n  requested folio size unsupported\n\nThe MAX_FOLIO_ORDER check was added by\ncommit 646b67d57589 (\"mm/memremap: reject unreasonable folio/compound\npage sizes in memremap_pages()\").\n\nFix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always\nrequest the largest order the kernel supports, in those cases, rather\nthan an out-of-range value.\n\nAlso fix the error path to propagate the actual error code from\ndevm_memremap_pages() instead of hard-coding -EFAULT, which was\nmasking the real -EINVAL return."
    }
  ],
  "id": "CVE-2026-43348",
  "lastModified": "2026-05-08T14:16:44.890",
  "metrics": {},
  "published": "2026-05-08T14:16:44.890",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a142ca4b6481e71498712800b20e0c0fcf02843b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-J2M4-498Q-2W8W

Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-08 15:31

Details

In the Linux kernel, the following vulnerability has been resolved:

mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER

When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and last_pfn, intending to use the largest compound page order both endpoints are aligned to.

However, this value is not clamped to MAX_FOLIO_ORDER, so a sufficiently aligned range (e.g. physical range [0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000 with 35 trailing zeros) can produce a shift larger than what memremap_pages() accepts, triggering a WARN and returning -EINVAL:

WARNING: ... memremap_pages+0x512/0x650 requested folio size unsupported

The MAX_FOLIO_ORDER check was added by commit 646b67d57589 ("mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages()").

Fix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always request the largest order the kernel supports, in those cases, rather than an out-of-range value.

Also fix the error path to propagate the actual error code from devm_memremap_pages() instead of hard-coding -EFAULT, which was masking the real -EINVAL return.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-43348"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-08T14:16:44Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER\n\nWhen registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel\ncomputes pgmap-\u003evmemmap_shift as the number of trailing zeros in the\nOR of start_pfn and last_pfn, intending to use the largest compound\npage order both endpoints are aligned to.\n\nHowever, this value is not clamped to MAX_FOLIO_ORDER, so a\nsufficiently aligned range (e.g. physical range\n[0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000\nwith 35 trailing zeros) can produce a shift larger than what\nmemremap_pages() accepts, triggering a WARN and returning -EINVAL:\n\n  WARNING: ... memremap_pages+0x512/0x650\n  requested folio size unsupported\n\nThe MAX_FOLIO_ORDER check was added by\ncommit 646b67d57589 (\"mm/memremap: reject unreasonable folio/compound\npage sizes in memremap_pages()\").\n\nFix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always\nrequest the largest order the kernel supports, in those cases, rather\nthan an out-of-range value.\n\nAlso fix the error path to propagate the actual error code from\ndevm_memremap_pages() instead of hard-coding -EFAULT, which was\nmasking the real -EINVAL return.",
  "id": "GHSA-j2m4-498q-2w8w",
  "modified": "2026-05-08T15:31:24Z",
  "published": "2026-05-08T15:31:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43348"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a142ca4b6481e71498712800b20e0c0fcf02843b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-43348 (GCVE-0-2026-43348)

FKIE_CVE-2026-43348

GHSA-J2M4-498Q-2W8W

Tags

Sightings

Nomenclature