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CVE-2026-68381 (GCVE-0-2026-68381)

Vulnerability from cvelistv5 – Published: 2026-08-10 12:03 – Updated: 2026-08-17 05:04
VLAI
Title
ksmbd: pin conn during async oplock break notification
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: pin conn during async oplock break notification smb2_oplock_break_noti() and smb2_lease_break_noti() store a ksmbd_conn pointer in an async ksmbd_work and then queue that work on ksmbd-io. The work only increments conn->r_count, which prevents teardown from passing the pending-request wait after the increment, but it does not pin the struct ksmbd_conn object. If connection teardown races with an oplock break notification, the last conn reference can be dropped before the queued worker finishes. The worker then uses the freed conn in ksmbd_conn_write() and ksmbd_conn_r_count_dec(). Take a real conn reference when publishing the conn pointer to the async work item, and drop it after the notification work has decremented r_count. Apply the same lifetime rule to lease break notification, which uses the same work->conn pattern.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 09aeab68033161cb54f194da93e51a11aee6144b , < 0f72fc9659d7f585460d43c158055df5afdcffb6 (git)
Affected: a4261bbc33fbf99b99c80aa3a2c5097611802980 , < 793e1c7041b93af96ff87e678329bc16aee7ba88 (git)
Affected: 3aa660c059240e0c795217182cf7df32909dd917 , < 6ecb252efa0b413ac3d9979fb4eec247f8fc1258 (git)
Affected: 3aa660c059240e0c795217182cf7df32909dd917 , < 14062c74e5b25c27edcff7a2fe0dc701c930b372 (git)
Affected: 3aa660c059240e0c795217182cf7df32909dd917 , < aa5d8f3f96aa11a4a54ce993c11ce8af11c546f9 (git)
Affected: f17d1c63a76b0fe8e9c78023a86507a3a6d62cfa (git)
Affected: 6.6.84 , < 6.6.148 (semver)
Affected: 6.12.20 , < 6.12.101 (semver)
Affected: 6.13.8 , < 6.14 (semver)
guessed Create a notification for this product.
Linux Linux Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 6.6.148 , ≤ 6.6.* (semver)
Unaffected: 6.12.101 , ≤ 6.12.* (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: pin conn during async oplock break notification\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() store a ksmbd_conn\npointer in an async ksmbd_work and then queue that work on ksmbd-io.  The\nwork only increments conn-\u003er_count, which prevents teardown from passing\nthe pending-request wait after the increment, but it does not pin the\nstruct ksmbd_conn object.\n\nIf connection teardown races with an oplock break notification, the last\nconn reference can be dropped before the queued worker finishes.  The\nworker then uses the freed conn in ksmbd_conn_write() and\nksmbd_conn_r_count_dec().\n\nTake a real conn reference when publishing the conn pointer to the async\nwork item, and drop it after the notification work has decremented\nr_count.  Apply the same lifetime rule to lease break notification, which\nuses the same work-\u003econn pattern."
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    "datePublished": "2026-08-10T12:03:59.849Z",
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    "dateUpdated": "2026-08-17T05:04:27.523Z",
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    "redhat_vex": {
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      "current_release_date": "2026-08-31T05:26:21+00:00",
      "cve": "CVE-2026-68381",
      "id": "CVE-2026-68381",
      "initial_release_date": "2026-08-10T12:03:59.849000+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ksmbd: Use-after-free vulnerability due to race condition in connection handling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68381.json",
      "version": "3"
    },
    "suse_vex": {
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      "current_release_date": "2026-08-13T01:28:08Z",
      "cve": "CVE-2026-68381",
      "id": "CVE-2026-68381",
      "initial_release_date": "2026-08-12T16:22:29Z",
      "product_status:known_not_affected": "296",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-68381",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68381.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.