Vulnerability-Lookup

GHSA-P5MP-QV23-7R77

Vulnerability from github – Published: 2025-12-16 15:30 – Updated: 2026-07-30 06:32

Details

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

ceph: fix multifs mds auth caps issue

The mds auth caps check should also validate the fsname along with the associated caps. Not doing so would result in applying the mds auth caps of one fs on to the other fs in a multifs ceph cluster. The bug causes multiple issues w.r.t user authentication, following is one such example.

Steps to Reproduce (on vstart cluster): 1. Create two file systems in a cluster, say 'fsname1' and 'fsname2' 2. Authorize read only permission to the user 'client.usr' on fs 'fsname1' $ceph fs authorize fsname1 client.usr / r 3. Authorize read and write permission to the same user 'client.usr' on fs 'fsname2' $ceph fs authorize fsname2 client.usr / rw 4. Update the keyring $ceph auth get client.usr >> ./keyring

With above permssions for the user 'client.usr', following is the expectation. a. The 'client.usr' should be able to only read the contents and not allowed to create or delete files on file system 'fsname1'. b. The 'client.usr' should be able to read/write on file system 'fsname2'.

But, with this bug, the 'client.usr' is allowed to read/write on file system 'fsname1'. See below.

Mount the file system 'fsname1' with the user 'client.usr' $sudo bin/mount.ceph usr@.fsname1=/ /kmnt_fsname1_usr/
Try creating a file on file system 'fsname1' with user 'client.usr'. This should fail but passes with this bug. $touch /kmnt_fsname1_usr/file1
Mount the file system 'fsname1' with the user 'client.admin' and create a file. $sudo bin/mount.ceph admin@.fsname1=/ /kmnt_fsname1_admin $echo "data" > /kmnt_fsname1_admin/admin_file1
Try removing an existing file on file system 'fsname1' with the user 'client.usr'. This shoudn't succeed but succeeds with the bug. $rm -f /kmnt_fsname1_usr/admin_file1

For more information, please take a look at the corresponding mds/fuse patch and tests added by looking into the tracker mentioned below.

v2: Fix a possible null dereference in doutc v3: Don't store fsname from mdsmap, validate against ceph_mount_options's fsname and use it v4: Code refactor, better warning message and fix possible compiler warning

[ Slava.Dubeyko: "fsname check failed" -> "fsname mismatch" ]

Severity

8.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2025-40362"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-12-16T14:15:48Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix multifs mds auth caps issue\n\nThe mds auth caps check should also validate the\nfsname along with the associated caps. Not doing\nso would result in applying the mds auth caps of\none fs on to the other fs in a multifs ceph cluster.\nThe bug causes multiple issues w.r.t user\nauthentication, following is one such example.\n\nSteps to Reproduce (on vstart cluster):\n1. Create two file systems in a cluster, say \u0027fsname1\u0027 and \u0027fsname2\u0027\n2. Authorize read only permission to the user \u0027client.usr\u0027 on fs \u0027fsname1\u0027\n    $ceph fs authorize fsname1 client.usr / r\n3. Authorize read and write permission to the same user \u0027client.usr\u0027 on fs \u0027fsname2\u0027\n    $ceph fs authorize fsname2 client.usr / rw\n4. Update the keyring\n    $ceph auth get client.usr \u003e\u003e ./keyring\n\nWith above permssions for the user \u0027client.usr\u0027, following is the\nexpectation.\n  a. The \u0027client.usr\u0027 should be able to only read the contents\n     and not allowed to create or delete files on file system \u0027fsname1\u0027.\n  b. The \u0027client.usr\u0027 should be able to read/write on file system \u0027fsname2\u0027.\n\nBut, with this bug, the \u0027client.usr\u0027 is allowed to read/write on file\nsystem \u0027fsname1\u0027. See below.\n\n5. Mount the file system \u0027fsname1\u0027 with the user \u0027client.usr\u0027\n     $sudo bin/mount.ceph usr@.fsname1=/ /kmnt_fsname1_usr/\n6. Try creating a file on file system \u0027fsname1\u0027 with user \u0027client.usr\u0027. This\n   should fail but passes with this bug.\n     $touch /kmnt_fsname1_usr/file1\n7. Mount the file system \u0027fsname1\u0027 with the user \u0027client.admin\u0027 and create a\n   file.\n     $sudo bin/mount.ceph admin@.fsname1=/ /kmnt_fsname1_admin\n     $echo \"data\" \u003e /kmnt_fsname1_admin/admin_file1\n8. Try removing an existing file on file system \u0027fsname1\u0027 with the user\n   \u0027client.usr\u0027. This shoudn\u0027t succeed but succeeds with the bug.\n     $rm -f /kmnt_fsname1_usr/admin_file1\n\nFor more information, please take a look at the corresponding mds/fuse patch\nand tests added by looking into the tracker mentioned below.\n\nv2: Fix a possible null dereference in doutc\nv3: Don\u0027t store fsname from mdsmap, validate against\n    ceph_mount_options\u0027s fsname and use it\nv4: Code refactor, better warning message and\n    fix possible compiler warning\n\n[ Slava.Dubeyko: \"fsname check failed\" -\u003e \"fsname mismatch\" ]",
  "id": "GHSA-p5mp-qv23-7r77",
  "modified": "2026-07-30T06:32:23Z",
  "published": "2025-12-16T15:30:43Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40362"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/07640d34a781bb2e39020a39137073c03c4aa932"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/22c73d52a6d05c5a2053385c0d6cd9984732799d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2025-40362 (GCVE-0-2025-40362)

Vulnerability from cvelistv5 – Published: 2025-12-16 13:40 – Updated: 2026-10-15 22:02

Title

ceph: fix multifs mds auth caps issue

Summary

In the Linux kernel, the following vulnerability has been resolved: ceph: fix multifs mds auth caps issue The mds auth caps check should also validate the fsname along with the associated caps. Not doing so would result in applying the mds auth caps of one fs on to the other fs in a multifs ceph cluster. The bug causes multiple issues w.r.t user authentication, following is one such example. Steps to Reproduce (on vstart cluster): 1. Create two file systems in a cluster, say 'fsname1' and 'fsname2' 2. Authorize read only permission to the user 'client.usr' on fs 'fsname1' $ceph fs authorize fsname1 client.usr / r 3. Authorize read and write permission to the same user 'client.usr' on fs 'fsname2' $ceph fs authorize fsname2 client.usr / rw 4. Update the keyring $ceph auth get client.usr >> ./keyring With above permssions for the user 'client.usr', following is the expectation. a. The 'client.usr' should be able to only read the contents and not allowed to create or delete files on file system 'fsname1'. b. The 'client.usr' should be able to read/write on file system 'fsname2'. But, with this bug, the 'client.usr' is allowed to read/write on file system 'fsname1'. See below. 5. Mount the file system 'fsname1' with the user 'client.usr' $sudo bin/mount.ceph usr@.fsname1=/ /kmnt_fsname1_usr/ 6. Try creating a file on file system 'fsname1' with user 'client.usr'. This should fail but passes with this bug. $touch /kmnt_fsname1_usr/file1 7. Mount the file system 'fsname1' with the user 'client.admin' and create a file. $sudo bin/mount.ceph admin@.fsname1=/ /kmnt_fsname1_admin $echo "data" > /kmnt_fsname1_admin/admin_file1 8. Try removing an existing file on file system 'fsname1' with the user 'client.usr'. This shoudn't succeed but succeeds with the bug. $rm -f /kmnt_fsname1_usr/admin_file1 For more information, please take a look at the corresponding mds/fuse patch and tests added by looking into the tracker mentioned below. v2: Fix a possible null dereference in doutc v3: Don't store fsname from mdsmap, validate against ceph_mount_options's fsname and use it v4: Code refactor, better warning message and fix possible compiler warning [ Slava.Dubeyko: "fsname check failed" -> "fsname mismatch" ]

Severity

8.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-15 21:59 UTC

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6639 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/07640d34a781bb2e3…
https://git.kernel.org/stable/c/ca3da8b27ab9a0923…
https://git.kernel.org/stable/c/22c73d52a6d05c5a2…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 596afb0b8933ba6ed7227adcc538db26feb25c74 , < 07640d34a781bb2e39020a39137073c03c4aa932 (git) Affected: 596afb0b8933ba6ed7227adcc538db26feb25c74 , < ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523 (git) Affected: 596afb0b8933ba6ed7227adcc538db26feb25c74 , < 22c73d52a6d05c5a2053385c0d6cd9984732799d (git)
Linux	Linux	Affected: 6.10 Unaffected: 0 , < 6.10 (semver) Unaffected: 6.12.58 , ≤ 6.12.* (semver) Unaffected: 6.17.8 , ≤ 6.17.* (semver) Unaffected: 6.18 , ≤ * (original_commit_for_fix)

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{
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                "id": "CVE-2025-40362",
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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

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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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