Vulnerability-Lookup

GHSA-RGF4-V7FW-49XJ

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-14 15:32

Details

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

ceph: bound copied dentry name length in NFS export get_name

ceph_get_name() copies the MDS-supplied name into the caller's NAME_MAX-sized buffer with memcpy(name, rinfo->dname, rinfo->dname_len) and then writes name[rinfo->dname_len] = 0, without checking dname_len against NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply with dname_len > NAME_MAX overflows the buffer. __get_snap_name() copies rde->name / rde->name_len the same unchecked way.

Impact: a malicious or compromised Ceph MDS overflows the NAME_MAX name buffer in a client's NFS-export get_name path, a slab out-of-bounds write reported by KASAN. Reachable when a CephFS mount is re-exported over NFS.

Add ceph_export_copy_name(), which rejects lengths above NAME_MAX with -ENAMETOOLONG before the copy, and use it in both ceph_get_name() and __get_snap_name().

Severity

9.8 (Critical)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89652"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:51Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: bound copied dentry name length in NFS export get_name\n\nceph_get_name() copies the MDS-supplied name into the caller\u0027s\nNAME_MAX-sized buffer with memcpy(name, rinfo-\u003edname, rinfo-\u003edname_len)\nand then writes name[rinfo-\u003edname_len] = 0, without checking dname_len\nagainst NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply\nwith dname_len \u003e NAME_MAX overflows the buffer. __get_snap_name() copies\nrde-\u003ename / rde-\u003ename_len the same unchecked way.\n\nImpact: a malicious or compromised Ceph MDS overflows the NAME_MAX name\nbuffer in a client\u0027s NFS-export get_name path, a slab out-of-bounds write\nreported by KASAN. Reachable when a CephFS mount is re-exported over NFS.\n\nAdd ceph_export_copy_name(), which rejects lengths above NAME_MAX with\n-ENAMETOOLONG before the copy, and use it in both ceph_get_name() and\n__get_snap_name().",
  "id": "GHSA-rgf4-v7fw-49xj",
  "modified": "2026-09-14T15:32:32Z",
  "published": "2026-09-11T21:31:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89652"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/06fb5e623cdc2402d6bb29be94d9beb9a826ffec"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/61d9f27b191b838b96b697ce0bfaee39a138243a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a294064e0e0f81ea607b2f019e16888aa1b0a011"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eff8013c5a8916613c742ae5a2cc341cb605c0ae"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-89652 (GCVE-0-2026-89652)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:45 – Updated: 2026-09-14 12:01

Title

ceph: bound copied dentry name length in NFS export get_name

Summary

In the Linux kernel, the following vulnerability has been resolved: ceph: bound copied dentry name length in NFS export get_name ceph_get_name() copies the MDS-supplied name into the caller's NAME_MAX-sized buffer with memcpy(name, rinfo->dname, rinfo->dname_len) and then writes name[rinfo->dname_len] = 0, without checking dname_len against NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply with dname_len > NAME_MAX overflows the buffer. __get_snap_name() copies rde->name / rde->name_len the same unchecked way. Impact: a malicious or compromised Ceph MDS overflows the NAME_MAX name buffer in a client's NFS-export get_name path, a slab out-of-bounds write reported by KASAN. Reachable when a CephFS mount is re-exported over NFS. Add ceph_export_copy_name(), which rejects lengths above NAME_MAX with -ENAMETOOLONG before the copy, and use it in both ceph_get_name() and __get_snap_name().

Severity

9.8 (Critical)


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

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/a294064e0e0f81ea6…
https://git.kernel.org/stable/c/61d9f27b191b838b9…
https://git.kernel.org/stable/c/06fb5e623cdc2402d…
https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd…
https://git.kernel.org/stable/c/eff8013c5a8916613…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 19913b4eac4a230dccb548931358398f45dabe4c , < a294064e0e0f81ea607b2f019e16888aa1b0a011 (git) Affected: 19913b4eac4a230dccb548931358398f45dabe4c , < 61d9f27b191b838b96b697ce0bfaee39a138243a (git) Affected: 19913b4eac4a230dccb548931358398f45dabe4c , < 06fb5e623cdc2402d6bb29be94d9beb9a826ffec (git) Affected: 19913b4eac4a230dccb548931358398f45dabe4c , < e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6 (git) Affected: 19913b4eac4a230dccb548931358398f45dabe4c , < eff8013c5a8916613c742ae5a2cc341cb605c0ae (git)
Linux	Linux	Affected: 3.15 Unaffected: 0 , < 3.15 (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.109 , ≤ 6.12.* (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ceph/export.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a294064e0e0f81ea607b2f019e16888aa1b0a011",
              "status": "affected",
              "version": "19913b4eac4a230dccb548931358398f45dabe4c",
              "versionType": "git"
            },
            {
              "lessThan": "61d9f27b191b838b96b697ce0bfaee39a138243a",
              "status": "affected",
              "version": "19913b4eac4a230dccb548931358398f45dabe4c",
              "versionType": "git"
            },
            {
              "lessThan": "06fb5e623cdc2402d6bb29be94d9beb9a826ffec",
              "status": "affected",
              "version": "19913b4eac4a230dccb548931358398f45dabe4c",
              "versionType": "git"
            },
            {
              "lessThan": "e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6",
              "status": "affected",
              "version": "19913b4eac4a230dccb548931358398f45dabe4c",
              "versionType": "git"
            },
            {
              "lessThan": "eff8013c5a8916613c742ae5a2cc341cb605c0ae",
              "status": "affected",
              "version": "19913b4eac4a230dccb548931358398f45dabe4c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ceph/export.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.15"
            },
            {
              "lessThan": "3.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "versionStartIncluding": "3.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "3.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "3.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "3.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "3.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: bound copied dentry name length in NFS export get_name\n\nceph_get_name() copies the MDS-supplied name into the caller\u0027s\nNAME_MAX-sized buffer with memcpy(name, rinfo-\u003edname, rinfo-\u003edname_len)\nand then writes name[rinfo-\u003edname_len] = 0, without checking dname_len\nagainst NAME_MAX. A malicious or buggy MDS that returns a LOOKUPNAME reply\nwith dname_len \u003e NAME_MAX overflows the buffer. __get_snap_name() copies\nrde-\u003ename / rde-\u003ename_len the same unchecked way.\n\nImpact: a malicious or compromised Ceph MDS overflows the NAME_MAX name\nbuffer in a client\u0027s NFS-export get_name path, a slab out-of-bounds write\nreported by KASAN. Reachable when a CephFS mount is re-exported over NFS.\n\nAdd ceph_export_copy_name(), which rejects lengths above NAME_MAX with\n-ENAMETOOLONG before the copy, and use it in both ceph_get_name() and\n__get_snap_name()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - ceph_get_name() copies LOOKUPNAME/LSSNAP dentry names from a Ceph MDS reply over TCP, and nfsd reaches that callback via exportfs_decode_fh_raw() when CephFS is re-exported, so a remote MDS (or NFS client against such a gateway) hits the overflow on the network path.\nAC:L - A malicious MDS fully controls dname_len and the name bytes. nfsd lookup of a Ceph directory uses d_obtain_alias() then reconnect_path(), which deterministically calls get_name; no race, rare config, or uncontrollable layout is required.\nPR:N - No local account or capability on the victim is needed. A compromised or malicious MDS supplies the overflowing name, and on NFS-reexported CephFS any remote NFS client can force LOOKUPNAME by presenting a directory filehandle.\nUI:N - Once CephFS is mounted and re-exported over NFS, nfsd directory filehandle resolution automatically issues LOOKUPNAME and copies the MDS reply; no extra victim mount, click, or interactive step is required at exploit time.\nS:U - The overflow corrupts kernel stack/memory on the NFS/Ceph client host and does not cross a VM, IOMMU, or other security-authority boundary.\nC:H - Unbounded memcpy of MDS-controlled name bytes past the NAME_MAX+1 exportfs buffer is memory corruption that can overwrite adjacent kernel objects and be leveraged for arbitrary disclosure.\nI:H - Attacker-controlled length and contents overflow the NAME_MAX+1 stack buffer in exportfs_decode_fh_raw(), enabling an arbitrary write and control-flow hijacking.\nA:H - The same out-of-bounds write of a 256-byte name buffer by an MDS-chosen length, reported as a KASAN OOB write, reliably oopses or panics the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-14T12:01:47.069Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a294064e0e0f81ea607b2f019e16888aa1b0a011"
        },
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          "url": "https://git.kernel.org/stable/c/61d9f27b191b838b96b697ce0bfaee39a138243a"
        },
        {
          "url": "https://git.kernel.org/stable/c/06fb5e623cdc2402d6bb29be94d9beb9a826ffec"
        },
        {
          "url": "https://git.kernel.org/stable/c/e7c2fd3893a7f7fcd7e8cf0b2c6348bb1e893df6"
        },
        {
          "url": "https://git.kernel.org/stable/c/eff8013c5a8916613c742ae5a2cc341cb605c0ae"
        }
      ],
      "title": "ceph: bound copied dentry name length in NFS export get_name",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89652",
    "datePublished": "2026-09-11T19:45:42.443Z",
    "dateReserved": "2026-09-11T19:38:34.742Z",
    "dateUpdated": "2026-09-14T12:01:47.069Z",
    "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.

Detection rules are retrieved from Rulezet.

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-RGF4-V7FW-49XJ

CVE-2026-89652 (GCVE-0-2026-89652)

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Nomenclature