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GHSA-52G3-8W7F-V5W2

Vulnerability from github – Published: 2026-09-17 18:31 – Updated: 2026-09-17 18:31

Details

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

ksmbd: detach blocked lock requests before freeing

A file_lock retained by ksmbd for byte-range lock bookkeeping can still be part of the VFS blocked-request graph. In particular, the VFS can chain a new waiter below an already blocked request through flc_blocked_requests. The ksmbd_file reference count does not cover that graph.

Both __ksmbd_close_fd() and the cross-request unlock path free these retained file_lock objects directly. If a dependent waiter is still attached, locks_release_private() hits BUG_ON(!list_empty(&flc->flc_blocked_requests)). The same lifetime mismatch can leave a freed ksmbd_lock reachable through its request-local llist.

Detach the file_lock from the blocked-request graph before freeing it in the close, cross-request unlock, and rollback paths. locks_delete_block() also wakes requests chained below the object. Remove llist when a completed lock is published so a globally visible ksmbd_lock no longer points into the submitting worker's stack.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-90155"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-17T17:17:08Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: detach blocked lock requests before freeing\n\nA file_lock retained by ksmbd for byte-range lock bookkeeping can still\nbe part of the VFS blocked-request graph. In particular, the VFS can\nchain a new waiter below an already blocked request through\nflc_blocked_requests. The ksmbd_file reference count does not cover that\ngraph.\n\nBoth __ksmbd_close_fd() and the cross-request unlock path free these\nretained file_lock objects directly. If a dependent waiter is still\nattached, locks_release_private() hits\nBUG_ON(!list_empty(\u0026flc-\u003eflc_blocked_requests)). The same lifetime\nmismatch can leave a freed ksmbd_lock reachable through its request-local\nllist.\n\nDetach the file_lock from the blocked-request graph before freeing it in\nthe close, cross-request unlock, and rollback paths. locks_delete_block()\nalso wakes requests chained below the object. Remove llist when a\ncompleted lock is published so a globally visible ksmbd_lock no longer\npoints into the submitting worker\u0027s stack.",
  "id": "GHSA-52g3-8w7f-v5w2",
  "modified": "2026-09-17T18:31:53Z",
  "published": "2026-09-17T18:31:52Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90155"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/215e8816b1ac25176d911abb8704390413ccee4b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/514a0b2bc949963497e66cacd433f65dc768a71d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-90155 (GCVE-0-2026-90155)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:06 – Updated: 2026-09-17 16:06

Title

ksmbd: detach blocked lock requests before freeing

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: detach blocked lock requests before freeing A file_lock retained by ksmbd for byte-range lock bookkeeping can still be part of the VFS blocked-request graph. In particular, the VFS can chain a new waiter below an already blocked request through flc_blocked_requests. The ksmbd_file reference count does not cover that graph. Both __ksmbd_close_fd() and the cross-request unlock path free these retained file_lock objects directly. If a dependent waiter is still attached, locks_release_private() hits BUG_ON(!list_empty(&flc->flc_blocked_requests)). The same lifetime mismatch can leave a freed ksmbd_lock reachable through its request-local llist. Detach the file_lock from the blocked-request graph before freeing it in the close, cross-request unlock, and rollback paths. locks_delete_block() also wakes requests chained below the object. Remove llist when a completed lock is published so a globally visible ksmbd_lock no longer points into the submitting worker's stack.

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/514a0b2bc94996349…
https://git.kernel.org/stable/c/215e8816b1ac25176…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: d63528eb0d43c4796c42aad56889dec12cf4e122 , < 514a0b2bc949963497e66cacd433f65dc768a71d (git) Affected: d63528eb0d43c4796c42aad56889dec12cf4e122 , < 215e8816b1ac25176d911abb8704390413ccee4b (git)
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c",
            "fs/smb/server/vfs_cache.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "514a0b2bc949963497e66cacd433f65dc768a71d",
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              "version": "d63528eb0d43c4796c42aad56889dec12cf4e122",
              "versionType": "git"
            },
            {
              "lessThan": "215e8816b1ac25176d911abb8704390413ccee4b",
              "status": "affected",
              "version": "d63528eb0d43c4796c42aad56889dec12cf4e122",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c",
            "fs/smb/server/vfs_cache.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
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              "versionType": "semver"
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              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: detach blocked lock requests before freeing\n\nA file_lock retained by ksmbd for byte-range lock bookkeeping can still\nbe part of the VFS blocked-request graph. In particular, the VFS can\nchain a new waiter below an already blocked request through\nflc_blocked_requests. The ksmbd_file reference count does not cover that\ngraph.\n\nBoth __ksmbd_close_fd() and the cross-request unlock path free these\nretained file_lock objects directly. If a dependent waiter is still\nattached, locks_release_private() hits\nBUG_ON(!list_empty(\u0026flc-\u003eflc_blocked_requests)). The same lifetime\nmismatch can leave a freed ksmbd_lock reachable through its request-local\nllist.\n\nDetach the file_lock from the blocked-request graph before freeing it in\nthe close, cross-request unlock, and rollback paths. locks_delete_block()\nalso wakes requests chained below the object. Remove llist when a\ncompleted lock is published so a globally visible ksmbd_lock no longer\npoints into the submitting worker\u0027s stack."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-17T16:06:47.716Z",
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      ],
      "title": "ksmbd: detach blocked lock requests before freeing",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90155",
    "datePublished": "2026-09-17T16:06:47.716Z",
    "dateReserved": "2026-09-11T19:38:34.790Z",
    "dateUpdated": "2026-09-17T16:06:47.716Z",
    "state": "PUBLISHED"
  },
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
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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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GHSA-52G3-8W7F-V5W2

CVE-2026-90155 (GCVE-0-2026-90155)

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