Vulnerability-Lookup

GHSA-P68H-C56F-P3V6

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

Details

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

smb: client: split cached_fid bitfields to avoid shared-byte RMW races

is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. orb $mask, addr on x86_64), so updating one flag can restore stale values of the others.

A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits

To avoid this class of races, convert these flags to separate bool fields.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-23230"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-18T16:22:32Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: split cached_fid bitfields to avoid shared-byte RMW races\n\nis_open, has_lease and on_list are stored in the same bitfield byte in\nstruct cached_fid but are updated in different code paths that may run\nconcurrently. Bitfield assignments generate byte read\u2013modify\u2013write\noperations (e.g. `orb $mask, addr` on x86_64), so updating one flag can\nrestore stale values of the others.\n\nA possible interleaving is:\n    CPU1: load old byte (has_lease=1, on_list=1)\n    CPU2: clear both flags (store 0)\n    CPU1: RMW store (old | IS_OPEN) -\u003e reintroduces cleared bits\n\nTo avoid this class of races, convert these flags to separate bool\nfields.",
  "id": "GHSA-p68h-c56f-p3v6",
  "modified": "2026-02-18T18:30:40Z",
  "published": "2026-02-18T18:30:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23230"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4386f6af8aaedd0c5ad6f659b40cadcc8f423828"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c4b9edd55987384a1f201d3d07ff71e448d79c1b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-23230 (GCVE-0-2026-23230)

Vulnerability from cvelistv5 – Published: 2026-02-18 14:53 – Updated: 2026-02-18 14:53

Title

smb: client: split cached_fid bitfields to avoid shared-byte RMW races

Summary

In the Linux kernel, the following vulnerability has been resolved: smb: client: split cached_fid bitfields to avoid shared-byte RMW races is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can restore stale values of the others. A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits To avoid this class of races, convert these flags to separate bool fields.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/4386f6af8aaedd0c5…
	https://git.kernel.org/stable/c/3eaa22d688311c708…
	https://git.kernel.org/stable/c/c4b9edd55987384a1…
	https://git.kernel.org/stable/c/4cfa4c37dcbcfd708…

Impacted products

Vendor

Product

Version

Linux

Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 4386f6af8aaedd0c5ad6f659b40cadcc8f423828 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c4b9edd55987384a1f201d3d07ff71e448d79c1b (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 4cfa4c37dcbcfd70866e856200ed8a2894cac578 (git)

Linux

Unaffected: 6.6.125 , ≤ 6.6.* (semver)
Unaffected: 6.12.72 , ≤ 6.12.* (semver)
Unaffected: 6.18.11 , ≤ 6.18.* (semver)
Unaffected: 6.19.1 , ≤ 6.19.* (semver)

Show details on NVD website

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/cached_dir.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4386f6af8aaedd0c5ad6f659b40cadcc8f423828",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "3eaa22d688311c708b73f3c68bc6d0c8e3f0f77a",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
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              "status": "affected",
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              "versionType": "git"
            },
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              "status": "affected",
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              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/client/cached_dir.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.125",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.72",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.1",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.125",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.72",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.11",
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                },
                {
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      "descriptions": [
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: split cached_fid bitfields to avoid shared-byte RMW races\n\nis_open, has_lease and on_list are stored in the same bitfield byte in\nstruct cached_fid but are updated in different code paths that may run\nconcurrently. Bitfield assignments generate byte read\u2013modify\u2013write\noperations (e.g. `orb $mask, addr` on x86_64), so updating one flag can\nrestore stale values of the others.\n\nA possible interleaving is:\n    CPU1: load old byte (has_lease=1, on_list=1)\n    CPU2: clear both flags (store 0)\n    CPU1: RMW store (old | IS_OPEN) -\u003e reintroduces cleared bits\n\nTo avoid this class of races, convert these flags to separate bool\nfields."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-18T14:53:34.078Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
          "url": "https://git.kernel.org/stable/c/4cfa4c37dcbcfd70866e856200ed8a2894cac578"
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      ],
      "title": "smb: client: split cached_fid bitfields to avoid shared-byte RMW races",
      "x_generator": {
        "engine": "bippy-1.2.0"
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    }
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23230",
    "datePublished": "2026-02-18T14:53:34.078Z",
    "dateReserved": "2026-01-13T15:37:45.988Z",
    "dateUpdated": "2026-02-18T14:53:34.078Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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

GHSA-P68H-C56F-P3V6

CVE-2026-23230 (GCVE-0-2026-23230)

Tags

Sightings

Nomenclature