FKIE_CVE-2026-98897

Vulnerability from fkie_nvd - Published: 2026-10-23 12:18 - Updated: 2026-10-26 07:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: don't hold ci->m_lock while waiting for a lease break ack When a cifs.ko client caches a read-handle (RH) lease via deferred close and a conflicting open arrives, ksmbd breaks the lease and waits for the acknowledgment in wait_for_break_ack() for up to OPLOCK_WAIT_TIME (35s). __smb_break_all_levII_oplock() runs that wait while holding ci->m_lock for read. cifs.ko reacts to a handle-lease break by closing the deferred handle rather than sending a lease break acknowledgment. That close path (close_id_del_oplock() -> opinfo_del()) takes ci->m_lock for write and is exactly what would wake the waiter, but it blocks on the read lock held by the waiting thread. The break is then resolved only by the 35s timeout, so xfstests generic/001 takes ~78s with leases enabled versus ~4s with oplocks only. Collect the target opinfos (each pinned with a reference) while holding ci->m_lock, then break them after releasing it, matching how smb_grant_oplock() already breaks a conflicting lease using only a reference. The reference keeps the opinfo (and its conn and lease) alive across the unlocked window, and a close racing the break is handled by the existing OPLOCK_CLOSING state check. Apply the same fix to the parent lease break paths.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "868c9038ffd4af39766d087f68c8f543a3f66635",
              "status": "affected",
              "version": "d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b",
              "versionType": "git"
            },
            {
              "lessThan": "27a9bc968d4ae809a3f5ca2f2b136856ee613cb4",
              "status": "affected",
              "version": "d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "16ece7c5645a68efca22a0a69a7718c8e50c3232",
              "versionType": "git"
            },
            {
              "lessThan": "6.7",
              "status": "affected",
              "version": "6.6.35",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/oplock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: don\u0027t hold ci-\u003em_lock while waiting for a lease break ack\n\nWhen a cifs.ko client caches a read-handle (RH) lease via deferred close\nand a conflicting open arrives, ksmbd breaks the lease and waits for the\nacknowledgment in wait_for_break_ack() for up to OPLOCK_WAIT_TIME (35s).\n__smb_break_all_levII_oplock() runs that wait while holding ci-\u003em_lock\nfor read.\n\ncifs.ko reacts to a handle-lease break by closing the deferred handle\nrather than sending a lease break acknowledgment. That close path\n(close_id_del_oplock() -\u003e opinfo_del()) takes ci-\u003em_lock for write and\nis exactly what would wake the waiter, but it blocks on the read lock\nheld by the waiting thread. The break is then resolved only by the 35s\ntimeout, so xfstests generic/001 takes ~78s with leases enabled versus\n~4s with oplocks only.\n\nCollect the target opinfos (each pinned with a reference) while holding\nci-\u003em_lock, then break them after releasing it, matching how\nsmb_grant_oplock() already breaks a conflicting lease using only a\nreference.  The reference keeps the opinfo (and its conn and lease)\nalive across the unlocked window, and a close racing the break is\nhandled by the existing OPLOCK_CLOSING state check. Apply the same fix\nto the parent lease break paths."
    }
  ],
  "id": "CVE-2026-98897",
  "lastModified": "2026-10-26T07:17:14.980",
  "metrics": {},
  "published": "2026-10-23T12:18:23.670",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.