Vulnerability-Lookup

GHSA-5JGQ-PV8M-5CX7

Vulnerability from github – Published: 2026-02-18 18:30 – Updated: 2026-03-13 21:31

Details

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

ksmbd: add chann_lock to protect ksmbd_chann_list xarray

ksmbd_chann_list xarray lacks synchronization, allowing use-after-free in multi-channel sessions (between lookup_chann_list() and ksmbd_chann_del).

Adds rw_semaphore chann_lock to struct ksmbd_session and protects all xa_load/xa_store/xa_erase accesses.

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-2026-23226"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-18T16:22:32Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: add chann_lock to protect ksmbd_chann_list xarray\n\nksmbd_chann_list xarray lacks synchronization, allowing use-after-free in\nmulti-channel sessions (between lookup_chann_list() and ksmbd_chann_del).\n\nAdds rw_semaphore chann_lock to struct ksmbd_session and protects\nall xa_load/xa_store/xa_erase accesses.",
  "id": "GHSA-5jgq-pv8m-5cx7",
  "modified": "2026-03-13T21:31:40Z",
  "published": "2026-02-18T18:30:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23226"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/36ef605c0395b94b826a8c8d6f2697071173de6e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4c2ca31608521895dd742a43beca4b4d29762345"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4f3a06cc57976cafa8c6f716646be6c79a99e485"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e4a8a96a93d08570e0405cfd989a8a07e5b6ff33"
    }
  ],
  "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-2026-23226 (GCVE-0-2026-23226)

Vulnerability from cvelistv5 – Published: 2026-02-18 14:53 – Updated: 2026-08-05 12:20

Title

ksmbd: add chann_lock to protect ksmbd_chann_list xarray

Summary

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add chann_lock to protect ksmbd_chann_list xarray ksmbd_chann_list xarray lacks synchronization, allowing use-after-free in multi-channel sessions (between lookup_chann_list() and ksmbd_chann_del). Adds rw_semaphore chann_lock to struct ksmbd_session and protects all xa_load/xa_store/xa_erase accesses.

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

References

4 references

URL	Tags
https://git.kernel.org/stable/c/4c2ca31608521895d…
https://git.kernel.org/stable/c/e4a8a96a93d08570e…
https://git.kernel.org/stable/c/36ef605c0395b94b8…
https://git.kernel.org/stable/c/4f3a06cc57976cafa…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1d9c4172110e645b383ff13eee759728d74f1a5d , < 4c2ca31608521895dd742a43beca4b4d29762345 (git) Affected: 1d9c4172110e645b383ff13eee759728d74f1a5d , < e4a8a96a93d08570e0405cfd989a8a07e5b6ff33 (git) Affected: 1d9c4172110e645b383ff13eee759728d74f1a5d , < 36ef605c0395b94b826a8c8d6f2697071173de6e (git) Affected: 1d9c4172110e645b383ff13eee759728d74f1a5d , < 4f3a06cc57976cafa8c6f716646be6c79a99e485 (git) Affected: b1caecbf34b8c8260d851ec4efde71f3694460b7 (git) Affected: 91bbf9cb2387a0d76322e9a343bc6bc160f66b3f (git) Affected: 853c416710b075153c1e1421e099ffbe5dac68ce (git) Affected: 5.15.145 , < 5.16 (semver) Affected: 6.1.29 , < 6.2 (semver) Affected: 6.2.16 , < 6.3 (semver)
Linux	Linux	Affected: 6.3 Unaffected: 0 , < 6.3 (semver) Unaffected: 6.12.77 , ≤ 6.12.* (semver) Unaffected: 6.18.11 , ≤ 6.18.* (semver) Unaffected: 6.19.1 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c",
            "fs/smb/server/mgmt/user_session.h",
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4c2ca31608521895dd742a43beca4b4d29762345",
              "status": "affected",
              "version": "1d9c4172110e645b383ff13eee759728d74f1a5d",
              "versionType": "git"
            },
            {
              "lessThan": "e4a8a96a93d08570e0405cfd989a8a07e5b6ff33",
              "status": "affected",
              "version": "1d9c4172110e645b383ff13eee759728d74f1a5d",
              "versionType": "git"
            },
            {
              "lessThan": "36ef605c0395b94b826a8c8d6f2697071173de6e",
              "status": "affected",
              "version": "1d9c4172110e645b383ff13eee759728d74f1a5d",
              "versionType": "git"
            },
            {
              "lessThan": "4f3a06cc57976cafa8c6f716646be6c79a99e485",
              "status": "affected",
              "version": "1d9c4172110e645b383ff13eee759728d74f1a5d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b1caecbf34b8c8260d851ec4efde71f3694460b7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "91bbf9cb2387a0d76322e9a343bc6bc160f66b3f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "853c416710b075153c1e1421e099ffbe5dac68ce",
              "versionType": "git"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.145",
              "versionType": "semver"
            },
            {
              "lessThan": "6.2",
              "status": "affected",
              "version": "6.1.29",
              "versionType": "semver"
            },
            {
              "lessThan": "6.3",
              "status": "affected",
              "version": "6.2.16",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/user_session.c",
            "fs/smb/server/mgmt/user_session.h",
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.3"
            },
            {
              "lessThan": "6.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.77",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.77",
                  "versionStartIncluding": "6.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.11",
                  "versionStartIncluding": "6.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.1",
                  "versionStartIncluding": "6.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.145",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.1.29",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.2.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: add chann_lock to protect ksmbd_chann_list xarray\n\nksmbd_chann_list xarray lacks synchronization, allowing use-after-free in\nmulti-channel sessions (between lookup_chann_list() and ksmbd_chann_del).\n\nAdds rw_semaphore chann_lock to struct ksmbd_session and protects\nall xa_load/xa_store/xa_erase accesses."
        }
      ],
      "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 - ksmbd is the in-kernel SMB server listening on TCP port 445, directly reachable over the network.\nAC:L - The attacker controls both sides of the race by establishing multiple SMB connections (multi-channel session) and timing a disconnect on one while the other accesses the channel list. The attacker creates and controls the race condition.\nPR:L - The channel list is populated during ntlm_authenticate() or krb5_authenticate(), requiring valid SMB credentials to establish a session before the race can be triggered. This is post-authentication.\nUI:N - No user interaction is needed; the attacker initiates and controls all SMB connections and their timing.\nS:U - The vulnerability and its impact remain within the kernel security authority; no security boundary (e.g., VM, sandbox) is crossed.\nC:H - Use-after-free on struct channel allows reading freed memory that may be reallocated with attacker-controlled content, enabling arbitrary kernel memory disclosure including signing keys.\nI:H - Use-after-free enables heap spraying to replace the freed channel struct, allowing attacker-controlled data to be used as signing keys or function pointers, leading to arbitrary code execution.\nA:H - Use-after-free reliably causes kernel crashes (oops/panic) when the freed channel pointer is dereferenced, causing denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:20:44.508Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4c2ca31608521895dd742a43beca4b4d29762345"
        },
        {
          "url": "https://git.kernel.org/stable/c/e4a8a96a93d08570e0405cfd989a8a07e5b6ff33"
        },
        {
          "url": "https://git.kernel.org/stable/c/36ef605c0395b94b826a8c8d6f2697071173de6e"
        },
        {
          "url": "https://git.kernel.org/stable/c/4f3a06cc57976cafa8c6f716646be6c79a99e485"
        }
      ],
      "title": "ksmbd: add chann_lock to protect ksmbd_chann_list xarray",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23226",
    "datePublished": "2026-02-18T14:53:29.562Z",
    "dateReserved": "2026-01-13T15:37:45.987Z",
    "dateUpdated": "2026-08-05T12:20:44.508Z",
    "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.
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GHSA-5JGQ-PV8M-5CX7

CVE-2026-23226 (GCVE-0-2026-23226)

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