Vulnerability-Lookup

CVE-2026-98897 (GCVE-0-2026-98897)

Vulnerability from cvelistv5 – Published: 2026-10-23 11:54 – Updated: 2026-10-26 06:56

Title

ksmbd: don't hold ci->m_lock while waiting for a lease break ack

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.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7067 records in the last 180 days details

References

2 references

URL	Tags
https://git.kernel.org/stable/c/868c9038ffd4af397…
https://git.kernel.org/stable/c/27a9bc968d4ae809a…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b , < 868c9038ffd4af39766d087f68c8f543a3f66635 (git) Affected: d1c189c6cb8b0fb7b5ee549237d27889c40c2f8b , < 27a9bc968d4ae809a3f5ca2f2b136856ee613cb4 (git) Affected: 16ece7c5645a68efca22a0a69a7718c8e50c3232 (git) Affected: 6.6.35 , < 6.7 (semver)	guessed
Linux	Linux	Affected: 6.9 Unaffected: 0 , < 6.9 (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.6.35",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-26T06:56:24.210Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635"
        },
        {
          "url": "https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4"
        }
      ],
      "title": "ksmbd: don\u0027t hold ci-\u003em_lock while waiting for a lease break ack",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98897",
    "datePublished": "2026-10-23T11:54:05.872Z",
    "dateReserved": "2026-09-25T10:25:14.379Z",
    "dateUpdated": "2026-10-26T06:56:24.210Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-98897",
      "date": "2026-10-26",
      "epss": "0.00161",
      "percentile": "0.05277"
    },
    "microsoft_vex": {
      "current_release_date": "2026-10-24T01:05:37.000Z",
      "cve": "CVE-2026-98897",
      "id": "msrc_CVE-2026-98897",
      "initial_release_date": "2026-10-24T01:02:13.000Z",
      "product_status:known_affected": "1",
      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "ksmbd: don\u0027t hold ci-\u003em_lock while waiting for a lease break ack",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-98897.json",
      "version": "2"
    },
    "nvd": {
      "cve": {
        "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"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-26T17:03:31+00:00",
      "cve": "CVE-2026-98897",
      "id": "CVE-2026-98897",
      "initial_release_date": "2026-10-23T00:00:00+00:00",
      "product_status:known_affected": "77",
      "product_status:known_not_affected": "201",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ksmbd: don\u0027t hold ci-\u003em_lock while waiting for a lease break ack",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98897.json",
      "version": "3"
    }
  }
}

FKIE_CVE-2026-98897

Vulnerability from fkie_nvd - Published: 2026-10-23 12:18 - Updated: 2026-10-26 07:17

Severity

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635

Impacted products

	Vendor	Product	Version

JSON

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"
}

GHSA-83J5-G9M2-9MF4

Vulnerability from github – Published: 2026-10-23 12:31 – Updated: 2026-10-23 12:31

Details

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.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-98897"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-23T12:18:23Z",
    "severity": null
  },
  "details": "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": "GHSA-83j5-g9m2-9mf4",
  "modified": "2026-10-23T12:31:37Z",
  "published": "2026-10-23T12:31:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98897"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

MSRC_CVE-2026-98897

Vulnerability from csaf_microsoft - Published: 2026-10-24 01:02 - Updated: 2026-10-24 01:05

Summary

ksmbd: don't hold ci->m_lock while waiting for a lease break ack

Scope

1 vulnerability in this advisory, including CVE-2026-98897.

CVE-2026-98897

Known affected: 1 product Under investigation: 1 product

Open the full advisory

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

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.

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CVE-2026-98897 (GCVE-0-2026-98897)

FKIE_CVE-2026-98897

GHSA-83J5-G9M2-9MF4

MSRC_CVE-2026-98897

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Related by attack behaviour