Vulnerability-Lookup

CVE-2026-23177 (GCVE-0-2026-23177)

Vulnerability from cvelistv5 – Published: 2026-02-14 16:27 – Updated: 2026-02-14 16:27

Title

mm, shmem: prevent infinite loop on truncate race

Summary

In the Linux kernel, the following vulnerability has been resolved: mm, shmem: prevent infinite loop on truncate race When truncating a large swap entry, shmem_free_swap() returns 0 when the entry's index doesn't match the given index due to lookup alignment. The failure fallback path checks if the entry crosses the end border and aborts when it happens, so truncate won't erase an unexpected entry or range. But one scenario was ignored. When `index` points to the middle of a large swap entry, and the large swap entry doesn't go across the end border, find_get_entries() will return that large swap entry as the first item in the batch with `indices[0]` equal to `index`. The entry's base index will be smaller than `indices[0]`, so shmem_free_swap() will fail and return 0 due to the "base < index" check. The code will then call shmem_confirm_swap(), get the order, check if it crosses the END boundary (which it doesn't), and retry with the same index. The next iteration will find the same entry again at the same index with same indices, leading to an infinite loop. Fix this by retrying with a round-down index, and abort if the index is smaller than the truncate range.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/dfc3ab6bd64860f80…
	https://git.kernel.org/stable/c/7b6a0f121d50234aa…
	https://git.kernel.org/stable/c/2030dddf95451b4e7…

Impacted products

Vendor

Product

Version

Linux

Affected: 809bc86517cc408b5b8cb8e08e69096639432bc8 , < dfc3ab6bd64860f8022d69903be299d09be86e11 (git)
Affected: 809bc86517cc408b5b8cb8e08e69096639432bc8 , < 7b6a0f121d50234aab3e7ab9a62ebe826d40a32a (git)
Affected: 809bc86517cc408b5b8cb8e08e69096639432bc8 , < 2030dddf95451b4e7a389f052091e7c4b7b274c6 (git)

Linux

Affected: 6.12
Unaffected: 0 , < 6.12 (semver)
Unaffected: 6.12.70 , ≤ 6.12.* (semver)
Unaffected: 6.18.10 , ≤ 6.18.* (semver)
Unaffected: 6.19 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "mm/shmem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "dfc3ab6bd64860f8022d69903be299d09be86e11",
              "status": "affected",
              "version": "809bc86517cc408b5b8cb8e08e69096639432bc8",
              "versionType": "git"
            },
            {
              "lessThan": "7b6a0f121d50234aab3e7ab9a62ebe826d40a32a",
              "status": "affected",
              "version": "809bc86517cc408b5b8cb8e08e69096639432bc8",
              "versionType": "git"
            },
            {
              "lessThan": "2030dddf95451b4e7a389f052091e7c4b7b274c6",
              "status": "affected",
              "version": "809bc86517cc408b5b8cb8e08e69096639432bc8",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "mm/shmem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.70",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.70",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.10",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19",
                  "versionStartIncluding": "6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm, shmem: prevent infinite loop on truncate race\n\nWhen truncating a large swap entry, shmem_free_swap() returns 0 when the\nentry\u0027s index doesn\u0027t match the given index due to lookup alignment.  The\nfailure fallback path checks if the entry crosses the end border and\naborts when it happens, so truncate won\u0027t erase an unexpected entry or\nrange.  But one scenario was ignored.\n\nWhen `index` points to the middle of a large swap entry, and the large\nswap entry doesn\u0027t go across the end border, find_get_entries() will\nreturn that large swap entry as the first item in the batch with\n`indices[0]` equal to `index`.  The entry\u0027s base index will be smaller\nthan `indices[0]`, so shmem_free_swap() will fail and return 0 due to the\n\"base \u003c index\" check.  The code will then call shmem_confirm_swap(), get\nthe order, check if it crosses the END boundary (which it doesn\u0027t), and\nretry with the same index.\n\nThe next iteration will find the same entry again at the same index with\nsame indices, leading to an infinite loop.\n\nFix this by retrying with a round-down index, and abort if the index is\nsmaller than the truncate range."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-14T16:27:09.429Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/dfc3ab6bd64860f8022d69903be299d09be86e11"
        },
        {
          "url": "https://git.kernel.org/stable/c/7b6a0f121d50234aab3e7ab9a62ebe826d40a32a"
        },
        {
          "url": "https://git.kernel.org/stable/c/2030dddf95451b4e7a389f052091e7c4b7b274c6"
        }
      ],
      "title": "mm, shmem: prevent infinite loop on truncate race",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23177",
    "datePublished": "2026-02-14T16:27:09.429Z",
    "dateReserved": "2026-01-13T15:37:45.983Z",
    "dateUpdated": "2026-02-14T16:27:09.429Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-23177\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-02-14T17:15:55.430\",\"lastModified\":\"2026-02-14T17:15:55.430\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmm, shmem: prevent infinite loop on truncate race\\n\\nWhen truncating a large swap entry, shmem_free_swap() returns 0 when the\\nentry\u0027s index doesn\u0027t match the given index due to lookup alignment.  The\\nfailure fallback path checks if the entry crosses the end border and\\naborts when it happens, so truncate won\u0027t erase an unexpected entry or\\nrange.  But one scenario was ignored.\\n\\nWhen `index` points to the middle of a large swap entry, and the large\\nswap entry doesn\u0027t go across the end border, find_get_entries() will\\nreturn that large swap entry as the first item in the batch with\\n`indices[0]` equal to `index`.  The entry\u0027s base index will be smaller\\nthan `indices[0]`, so shmem_free_swap() will fail and return 0 due to the\\n\\\"base \u003c index\\\" check.  The code will then call shmem_confirm_swap(), get\\nthe order, check if it crosses the END boundary (which it doesn\u0027t), and\\nretry with the same index.\\n\\nThe next iteration will find the same entry again at the same index with\\nsame indices, leading to an infinite loop.\\n\\nFix this by retrying with a round-down index, and abort if the index is\\nsmaller than the truncate range.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2030dddf95451b4e7a389f052091e7c4b7b274c6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7b6a0f121d50234aab3e7ab9a62ebe826d40a32a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/dfc3ab6bd64860f8022d69903be299d09be86e11\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}

FKIE_CVE-2026-23177

Vulnerability from fkie_nvd - Published: 2026-02-14 17:15 - Updated: 2026-02-14 17:15

Severity ?

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2030dddf95451b4e7a389f052091e7c4b7b274c6
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7b6a0f121d50234aab3e7ab9a62ebe826d40a32a
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/dfc3ab6bd64860f8022d69903be299d09be86e11

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm, shmem: prevent infinite loop on truncate race\n\nWhen truncating a large swap entry, shmem_free_swap() returns 0 when the\nentry\u0027s index doesn\u0027t match the given index due to lookup alignment.  The\nfailure fallback path checks if the entry crosses the end border and\naborts when it happens, so truncate won\u0027t erase an unexpected entry or\nrange.  But one scenario was ignored.\n\nWhen `index` points to the middle of a large swap entry, and the large\nswap entry doesn\u0027t go across the end border, find_get_entries() will\nreturn that large swap entry as the first item in the batch with\n`indices[0]` equal to `index`.  The entry\u0027s base index will be smaller\nthan `indices[0]`, so shmem_free_swap() will fail and return 0 due to the\n\"base \u003c index\" check.  The code will then call shmem_confirm_swap(), get\nthe order, check if it crosses the END boundary (which it doesn\u0027t), and\nretry with the same index.\n\nThe next iteration will find the same entry again at the same index with\nsame indices, leading to an infinite loop.\n\nFix this by retrying with a round-down index, and abort if the index is\nsmaller than the truncate range."
    }
  ],
  "id": "CVE-2026-23177",
  "lastModified": "2026-02-14T17:15:55.430",
  "metrics": {},
  "published": "2026-02-14T17:15:55.430",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2030dddf95451b4e7a389f052091e7c4b7b274c6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7b6a0f121d50234aab3e7ab9a62ebe826d40a32a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dfc3ab6bd64860f8022d69903be299d09be86e11"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-XWQ7-47QJ-QWWF

Vulnerability from github – Published: 2026-02-14 18:30 – Updated: 2026-02-14 18:30

Details

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

mm, shmem: prevent infinite loop on truncate race

When truncating a large swap entry, shmem_free_swap() returns 0 when the entry's index doesn't match the given index due to lookup alignment. The failure fallback path checks if the entry crosses the end border and aborts when it happens, so truncate won't erase an unexpected entry or range. But one scenario was ignored.

When index points to the middle of a large swap entry, and the large swap entry doesn't go across the end border, find_get_entries() will return that large swap entry as the first item in the batch with indices[0] equal to index. The entry's base index will be smaller than indices[0], so shmem_free_swap() will fail and return 0 due to the "base < index" check. The code will then call shmem_confirm_swap(), get the order, check if it crosses the END boundary (which it doesn't), and retry with the same index.

The next iteration will find the same entry again at the same index with same indices, leading to an infinite loop.

Fix this by retrying with a round-down index, and abort if the index is smaller than the truncate range.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-23177"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-14T17:15:55Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm, shmem: prevent infinite loop on truncate race\n\nWhen truncating a large swap entry, shmem_free_swap() returns 0 when the\nentry\u0027s index doesn\u0027t match the given index due to lookup alignment.  The\nfailure fallback path checks if the entry crosses the end border and\naborts when it happens, so truncate won\u0027t erase an unexpected entry or\nrange.  But one scenario was ignored.\n\nWhen `index` points to the middle of a large swap entry, and the large\nswap entry doesn\u0027t go across the end border, find_get_entries() will\nreturn that large swap entry as the first item in the batch with\n`indices[0]` equal to `index`.  The entry\u0027s base index will be smaller\nthan `indices[0]`, so shmem_free_swap() will fail and return 0 due to the\n\"base \u003c index\" check.  The code will then call shmem_confirm_swap(), get\nthe order, check if it crosses the END boundary (which it doesn\u0027t), and\nretry with the same index.\n\nThe next iteration will find the same entry again at the same index with\nsame indices, leading to an infinite loop.\n\nFix this by retrying with a round-down index, and abort if the index is\nsmaller than the truncate range.",
  "id": "GHSA-xwq7-47qj-qwwf",
  "modified": "2026-02-14T18:30:16Z",
  "published": "2026-02-14T18:30:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23177"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2030dddf95451b4e7a389f052091e7c4b7b274c6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7b6a0f121d50234aab3e7ab9a62ebe826d40a32a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dfc3ab6bd64860f8022d69903be299d09be86e11"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date

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-2026-23177 (GCVE-0-2026-23177)

FKIE_CVE-2026-23177

GHSA-XWQ7-47QJ-QWWF

Tags

Sightings

Nomenclature