Vulnerability-Lookup

GHSA-C6C4-GFJC-9WRJ

Vulnerability from github – Published: 2025-07-25 18:30 – Updated: 2025-12-23 00:30

Details

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

ksmbd: fix potential use-after-free in oplock/lease break ack

If ksmbd_iov_pin_rsp return error, use-after-free can happen by accessing opinfo->state and opinfo_put and ksmbd_fd_put could called twice.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2025-38437"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-07-25T16:15:29Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix potential use-after-free in oplock/lease break ack\n\nIf ksmbd_iov_pin_rsp return error, use-after-free can happen by\naccessing opinfo-\u003estate and opinfo_put and ksmbd_fd_put could\ncalled twice.",
  "id": "GHSA-c6c4-gfjc-9wrj",
  "modified": "2025-12-23T00:30:29Z",
  "published": "2025-07-25T18:30:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38437"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/50f930db22365738d9387c974416f38a06e8057e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8106adc21a2270c16abf69cd74ccd7c79c6e7acd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/815f1161d6dbc4c54ccf94b7d3fdeab34b4d7477"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/97c355989928a5f60b228ef5266c1be67a46cdf9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e38ec88a2b42c494601b1213816d75f0b54d9bf0"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2025-38437 (GCVE-0-2025-38437)

Vulnerability from cvelistv5 – Published: 2025-07-25 15:27 – Updated: 2026-08-05 12:01

Title

ksmbd: fix potential use-after-free in oplock/lease break ack

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix potential use-after-free in oplock/lease break ack If ksmbd_iov_pin_rsp return error, use-after-free can happen by accessing opinfo->state and opinfo_put and ksmbd_fd_put could called twice.

Severity

8.8 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root Scorecard

References

6 references

URL	Tags
https://git.kernel.org/stable/c/e38ec88a2b42c4946…
https://git.kernel.org/stable/c/97c355989928a5f60…
https://git.kernel.org/stable/c/815f1161d6dbc4c54…
https://git.kernel.org/stable/c/8106adc21a2270c16…
https://git.kernel.org/stable/c/50f930db22365738d…
https://lists.debian.org/debian-lts-announce/2025…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < e38ec88a2b42c494601b1213816d75f0b54d9bf0 (git) Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 97c355989928a5f60b228ef5266c1be67a46cdf9 (git) Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 815f1161d6dbc4c54ccf94b7d3fdeab34b4d7477 (git) Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 8106adc21a2270c16abf69cd74ccd7c79c6e7acd (git) Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 50f930db22365738d9387c974416f38a06e8057e (git)
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 6.1.146 , ≤ 6.1.* (semver) Unaffected: 6.6.99 , ≤ 6.6.* (semver) Unaffected: 6.12.39 , ≤ 6.12.* (semver) Unaffected: 6.15.7 , ≤ 6.15.* (semver) Unaffected: 6.16 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T17:38:00.632Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
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          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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              "versionType": "git"
            },
            {
              "lessThan": "8106adc21a2270c16abf69cd74ccd7c79c6e7acd",
              "status": "affected",
              "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
              "versionType": "git"
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              "versionType": "git"
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          "defaultStatus": "affected",
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            "fs/smb/server/smb2pdu.c"
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "status": "unaffected",
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              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.99",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.15.*",
              "status": "unaffected",
              "version": "6.15.7",
              "versionType": "semver"
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            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.16",
              "versionType": "original_commit_for_fix"
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          "nodes": [
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                {
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                  "versionEndExcluding": "6.16",
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          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix potential use-after-free in oplock/lease break ack\n\nIf ksmbd_iov_pin_rsp return error, use-after-free can happen by\naccessing opinfo-\u003estate and opinfo_put and ksmbd_fd_put could\ncalled twice."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerable code is the ksmbd in-kernel SMB server\u0027s SMB2_OPLOCK_BREAK handler (fs/smb/server/smb2pdu.c), reached directly from an SMB2 PDU received on TCP/445. No local access is required.\nAC:L - The attacker fully controls both sides of the sequence \u2014 granting the oplock/lease, triggering the break from a second connection, and sending the ack \u2014 and can drive the only remaining condition (a `krealloc` failure under `__GFP_RETRY_MAYFAIL`, which fails instead of OOM-killing) by compounding many acks to force repeated iov growth while exhausting kernel memory with concurrent connections and large buffers.\nPR:L - `smb2_check_user_session()` rejects SMB2_OPLOCK_BREAK without a valid session, and the path needs a tree connect plus an open handle holding an oplock or lease, so a basic authenticated share user (or a guest account where the share permits it) is required.\nUI:N - The attacker performs every step \u2014 file open, conflicting open to force the break, and the oplock/lease break ack \u2014 with no action by any legitimate user or administrator.\nS:U - The corruption and its impact are confined to the kernel\u0027s own memory and the ksmbd server\u0027s security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The refcount underflow frees a still-linked `struct oplock_info` and an extra reference on `struct ksmbd_conn`/`struct ksmbd_file`, so subsequent dereferences of `opinfo-\u003econn`, `-\u003esess`, `-\u003eo_fp` and the waitqueue lists read heap the attacker can groom, yielding kernel memory disclosure.\nI:H - The freed object contains two list_heads and two wait_queue_heads still referenced by `fp-\u003ef_opinfo`, `ci-\u003em_op_list` and the lease table; reallocating it lets `wake_up_interruptible_all()` invoke an attacker-supplied `wait_queue_entry-\u003efunc` pointer and lets list unlink act as a write-what-where, giving arbitrary write and code execution.\nA:H - Even without successful exploitation the use-after-free, refcount underflow, and premature `__ksmbd_close_fd()`/connection release reliably produce oops or panic, and the attack can be repeated to keep the server down."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:01:53.911Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/e38ec88a2b42c494601b1213816d75f0b54d9bf0"
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          "url": "https://git.kernel.org/stable/c/97c355989928a5f60b228ef5266c1be67a46cdf9"
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        },
        {
          "url": "https://git.kernel.org/stable/c/50f930db22365738d9387c974416f38a06e8057e"
        }
      ],
      "title": "ksmbd: fix potential use-after-free in oplock/lease break ack",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-38437",
    "datePublished": "2025-07-25T15:27:16.995Z",
    "dateReserved": "2025-04-16T04:51:24.016Z",
    "dateUpdated": "2026-08-05T12:01:53.911Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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.

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GHSA-C6C4-GFJC-9WRJ

CVE-2025-38437 (GCVE-0-2025-38437)

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