CVE-2025-39927 (GCVE-0-2025-39927)

Vulnerability from cvelistv5 – Published: 2025-10-01 08:07 – Updated: 2026-08-05 12:06
VLAI
Title
ceph: fix race condition validating r_parent before applying state
Summary
In the Linux kernel, the following vulnerability has been resolved: ceph: fix race condition validating r_parent before applying state Add validation to ensure the cached parent directory inode matches the directory info in MDS replies. This prevents client-side race conditions where concurrent operations (e.g. rename) cause r_parent to become stale between request initiation and reply processing, which could lead to applying state changes to incorrect directory inodes. [ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to move CEPH_CAP_PIN reference when r_parent is updated: When the parent directory lock is not held, req->r_parent can become stale and is updated to point to the correct inode. However, the associated CEPH_CAP_PIN reference was not being adjusted. The CEPH_CAP_PIN is a reference on an inode that is tracked for accounting purposes. Moving this pin is important to keep the accounting balanced. When the pin was not moved from the old parent to the new one, it created two problems: The reference on the old, stale parent was never released, causing a reference leak. A reference for the new parent was never acquired, creating the risk of a reference underflow later in ceph_mdsc_release_request(). This patch corrects the logic by releasing the pin from the old parent and acquiring it for the new parent when r_parent is switched. This ensures reference accounting stays balanced. ]
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.7 (Medium)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 9030aaf9bf0a1eee47a154c316c789e959638b0f , < db378e6f83ec705c6091c65d482d555edc2b0a72 (git)
Affected: 9030aaf9bf0a1eee47a154c316c789e959638b0f , < 2bfe45987eb346e299d9f763f9cd05f77011519f (git)
Affected: 9030aaf9bf0a1eee47a154c316c789e959638b0f , < 15f519e9f883b316d86e2bb6b767a023aafd9d83 (git)
Create a notification for this product.
Linux Linux Affected: 2.6.34
Unaffected: 0 , < 2.6.34 (semver)
Unaffected: 6.12.48 , ≤ 6.12.* (semver)
Unaffected: 6.16.8 , ≤ 6.16.* (semver)
Unaffected: 6.17 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 4.7,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2025-39927",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-14T17:39:17.680672Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-362",
                "description": "CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization (\u0027Race Condition\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-14T17:42:45.563Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ceph/debugfs.c",
            "fs/ceph/dir.c",
            "fs/ceph/file.c",
            "fs/ceph/inode.c",
            "fs/ceph/mds_client.c",
            "fs/ceph/mds_client.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "db378e6f83ec705c6091c65d482d555edc2b0a72",
              "status": "affected",
              "version": "9030aaf9bf0a1eee47a154c316c789e959638b0f",
              "versionType": "git"
            },
            {
              "lessThan": "2bfe45987eb346e299d9f763f9cd05f77011519f",
              "status": "affected",
              "version": "9030aaf9bf0a1eee47a154c316c789e959638b0f",
              "versionType": "git"
            },
            {
              "lessThan": "15f519e9f883b316d86e2bb6b767a023aafd9d83",
              "status": "affected",
              "version": "9030aaf9bf0a1eee47a154c316c789e959638b0f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ceph/debugfs.c",
            "fs/ceph/dir.c",
            "fs/ceph/file.c",
            "fs/ceph/inode.c",
            "fs/ceph/mds_client.c",
            "fs/ceph/mds_client.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.34"
            },
            {
              "lessThan": "2.6.34",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.48",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.16.*",
              "status": "unaffected",
              "version": "6.16.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.17",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.48",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.16.8",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17",
                  "versionStartIncluding": "2.6.34",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix race condition validating r_parent before applying state\n\nAdd validation to ensure the cached parent directory inode matches the\ndirectory info in MDS replies. This prevents client-side race conditions\nwhere concurrent operations (e.g. rename) cause r_parent to become stale\nbetween request initiation and reply processing, which could lead to\napplying state changes to incorrect directory inodes.\n\n[ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to\n  move CEPH_CAP_PIN reference when r_parent is updated:\n\n  When the parent directory lock is not held, req-\u003er_parent can become\n  stale and is updated to point to the correct inode.  However, the\n  associated CEPH_CAP_PIN reference was not being adjusted.  The\n  CEPH_CAP_PIN is a reference on an inode that is tracked for\n  accounting purposes.  Moving this pin is important to keep the\n  accounting balanced. When the pin was not moved from the old parent\n  to the new one, it created two problems: The reference on the old,\n  stale parent was never released, causing a reference leak.\n  A reference for the new parent was never acquired, creating the risk\n  of a reference underflow later in ceph_mdsc_release_request().  This\n  patch corrects the logic by releasing the pin from the old parent and\n  acquiring it for the new parent when r_parent is switched.  This\n  ensures reference accounting stays balanced. ]"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The race is created entirely by concurrent local syscalls (path lookup driving `ceph_d_revalidate()` and `rename()`) on a mounted CephFS; no network-facing listener is involved, as the kernel here is the client consuming replies from its trusted MDS.\nAC:L - The attacker controls both sides of the race \u2014 one thread forces LOOKUP requests via lease-expired path walks, another repeatedly renames the target dentry between directories \u2014 and can retry indefinitely with no cost or side effects until the window is hit.\nPR:L - Only an unprivileged local account with access to the CephFS mount is needed; `ceph_d_revalidate()` sets `r_parent` without `CEPH_MDS_R_PARENT_LOCKED` on every ordinary path walk, and `rename()` within the attacker\u0027s own directories suffices to win the race.\nUI:N - The attacker\u0027s own two threads supply both the request and the concurrent rename; no action by any other user or administrator is required beyond the CephFS mount already existing.\nS:U - The corruption is confined to the kernel\u0027s own inode/cap/dcache state within the same security authority; no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - `ceph_fill_inode()` copies the foreign directory\u0027s mode, uid/gid, nlink, size, times, and its entire xattr blob (including security labels) onto an inode the attacker can then `stat`/`getxattr`, and the phantom caps installed by `ceph_add_cap()` make the client serve that stolen metadata indefinitely without revalidation.\nI:H - Ownership and permission bits of a directory inode are overwritten with another directory\u0027s values (e.g. an attacker-owned 0777 mode landing on a root-owned 0700 directory), and cap ids, snaprealm membership, and the dir-complete/empty flag are all corrupted, subverting the client\u0027s permission and consistency model.\nA:H - The cap id written by `ceph_add_cap()` no longer matches what the MDS issued for that inode, so cap flushes are rejected and threads block indefinitely on `i_cap_wq` (fsync/sync/umount hangs), while wrongly setting dir-complete with `i_size_write(inode, 0)` makes a live directory\u0027s entries unreachable for all users on the client."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:06:06.246Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/db378e6f83ec705c6091c65d482d555edc2b0a72"
        },
        {
          "url": "https://git.kernel.org/stable/c/2bfe45987eb346e299d9f763f9cd05f77011519f"
        },
        {
          "url": "https://git.kernel.org/stable/c/15f519e9f883b316d86e2bb6b767a023aafd9d83"
        }
      ],
      "title": "ceph: fix race condition validating r_parent before applying state",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-39927",
    "datePublished": "2025-10-01T08:07:14.595Z",
    "dateReserved": "2025-04-16T07:20:57.147Z",
    "dateUpdated": "2026-08-05T12:06:06.246Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-39927",
      "date": "2026-08-06",
      "epss": "0.00106",
      "percentile": "0.01276"
    },
    "microsoft_vex": {
      "current_release_date": "2026-06-28T01:44:03.000Z",
      "cve": "CVE-2025-39927",
      "id": "msrc_CVE-2025-39927",
      "initial_release_date": "2025-10-02T00:00:00.000Z",
      "product_status:known_affected": "18",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "ceph: fix race condition validating r_parent before applying state",
      "url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-39927.json",
      "version": "16"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-39927\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-10-01T08:15:36.097\",\"lastModified\":\"2026-07-30T06:23:57.103\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nceph: fix race condition validating r_parent before applying state\\n\\nAdd validation to ensure the cached parent directory inode matches the\\ndirectory info in MDS replies. This prevents client-side race conditions\\nwhere concurrent operations (e.g. rename) cause r_parent to become stale\\nbetween request initiation and reply processing, which could lead to\\napplying state changes to incorrect directory inodes.\\n\\n[ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to\\n  move CEPH_CAP_PIN reference when r_parent is updated:\\n\\n  When the parent directory lock is not held, req-\u003er_parent can become\\n  stale and is updated to point to the correct inode.  However, the\\n  associated CEPH_CAP_PIN reference was not being adjusted.  The\\n  CEPH_CAP_PIN is a reference on an inode that is tracked for\\n  accounting purposes.  Moving this pin is important to keep the\\n  accounting balanced. When the pin was not moved from the old parent\\n  to the new one, it created two problems: The reference on the old,\\n  stale parent was never released, causing a reference leak.\\n  A reference for the new parent was never acquired, creating the risk\\n  of a reference underflow later in ceph_mdsc_release_request().  This\\n  patch corrects the logic by releasing the pin from the old parent and\\n  acquiring it for the new parent when r_parent is switched.  This\\n  ensures reference accounting stays balanced. ]\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/ceph/debugfs.c\",\"fs/ceph/dir.c\",\"fs/ceph/file.c\",\"fs/ceph/inode.c\",\"fs/ceph/mds_client.c\",\"fs/ceph/mds_client.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"9030aaf9bf0a1eee47a154c316c789e959638b0f\",\"lessThan\":\"db378e6f83ec705c6091c65d482d555edc2b0a72\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9030aaf9bf0a1eee47a154c316c789e959638b0f\",\"lessThan\":\"2bfe45987eb346e299d9f763f9cd05f77011519f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"9030aaf9bf0a1eee47a154c316c789e959638b0f\",\"lessThan\":\"15f519e9f883b316d86e2bb6b767a023aafd9d83\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/ceph/debugfs.c\",\"fs/ceph/dir.c\",\"fs/ceph/file.c\",\"fs/ceph/inode.c\",\"fs/ceph/mds_client.c\",\"fs/ceph/mds_client.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.34\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.34\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.48\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.16.8\",\"lessThanOrEqual\":\"6.16.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.17\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":4.7,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.0,\"impactScore\":3.6},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":4.7,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.0,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-01-14T17:39:17.680672Z\",\"id\":\"CVE-2025-39927\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-362\"}]},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-362\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.6.35\",\"versionEndExcluding\":\"6.12.48\",\"matchCriteriaId\":\"5D43221C-9993-4996-B2D7-9EDB61ABD173\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.16.8\",\"matchCriteriaId\":\"8DA00A4E-AABB-4A69-AB39-67B22D0B36D2\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:2.6.34:-:*:*:*:*:*:*\",\"matchCriteriaId\":\"A3B1BC1D-ED46-4364-A1D9-1FA74182B03A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:2.6.34:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"86D3F64C-3F27-43E0-B0D4-62CE1E1F4EFB\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:2.6.34:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"7927713B-5EB0-41EB-86A9-9935775162E0\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:2.6.34:rc4:*:*:*:*:*:*\",\"matchCriteriaId\":\"59037296-3143-4FBB-AFF7-D4FE2C85502F\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:2.6.34:rc5:*:*:*:*:*:*\",\"matchCriteriaId\":\"9CA27FD5-7DBF-4C85-80A9-D523B2E4B033\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:2.6.34:rc6:*:*:*:*:*:*\",\"matchCriteriaId\":\"9711E333-A8E7-4F4B-BCFD-2023E889651A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:2.6.34:rc7:*:*:*:*:*:*\",\"matchCriteriaId\":\"E04D3358-973B-42A1-8E08-2E3AE947193C\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"327D22EF-390B-454C-BD31-2ED23C998A1C\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"C730CD9A-D969-4A8E-9522-162AAF7C0EE9\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"39982C4B-716E-4B2F-8196-FA301F47807D\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:*\",\"matchCriteriaId\":\"340BEEA9-D70D-4290-B502-FBB1032353B1\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:*\",\"matchCriteriaId\":\"47E4C5C0-079F-4838-971B-8C503D48FCC2\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/15f519e9f883b316d86e2bb6b767a023aafd9d83\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/2bfe45987eb346e299d9f763f9cd05f77011519f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/db378e6f83ec705c6091c65d482d555edc2b0a72\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-30T08:53:53+00:00",
      "cve": "CVE-2025-39927",
      "id": "CVE-2025-39927",
      "initial_release_date": "2025-10-01T00:00:00+00:00",
      "product_status:fixed": "279",
      "product_status:known_affected": "260",
      "product_status:known_not_affected": "14",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ceph: fix race condition validating r_parent before applying state",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-39927.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-07-15T06:00:53Z",
      "cve": "CVE-2025-39927",
      "id": "CVE-2025-39927",
      "initial_release_date": "2025-10-01T23:22:39Z",
      "product_status:first_fixed": "2",
      "product_status:known_affected": "341",
      "product_status:known_not_affected": "97",
      "product_status:recommended": "145",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-39927",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-39927.json",
      "version": "21"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 4.7, \"attackVector\": \"LOCAL\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2025-39927\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-01-14T17:39:17.680672Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-362\", \"description\": \"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization (\u0027Race Condition\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-01-14T17:39:13.495Z\"}}], \"cna\": {\"title\": \"ceph: fix race condition validating r_parent before applying state\", \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 7.8, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\"}}], \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"9030aaf9bf0a1eee47a154c316c789e959638b0f\", \"lessThan\": \"db378e6f83ec705c6091c65d482d555edc2b0a72\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"9030aaf9bf0a1eee47a154c316c789e959638b0f\", \"lessThan\": \"2bfe45987eb346e299d9f763f9cd05f77011519f\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"9030aaf9bf0a1eee47a154c316c789e959638b0f\", \"lessThan\": \"15f519e9f883b316d86e2bb6b767a023aafd9d83\", \"versionType\": \"git\"}], \"programFiles\": [\"fs/ceph/debugfs.c\", \"fs/ceph/dir.c\", \"fs/ceph/file.c\", \"fs/ceph/inode.c\", \"fs/ceph/mds_client.c\", \"fs/ceph/mds_client.h\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"2.6.34\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"2.6.34\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"6.12.48\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.12.*\"}, {\"status\": \"unaffected\", \"version\": \"6.16.8\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.16.*\"}, {\"status\": \"unaffected\", \"version\": \"6.17\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"fs/ceph/debugfs.c\", \"fs/ceph/dir.c\", \"fs/ceph/file.c\", \"fs/ceph/inode.c\", \"fs/ceph/mds_client.c\", \"fs/ceph/mds_client.h\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/db378e6f83ec705c6091c65d482d555edc2b0a72\"}, {\"url\": \"https://git.kernel.org/stable/c/2bfe45987eb346e299d9f763f9cd05f77011519f\"}, {\"url\": \"https://git.kernel.org/stable/c/15f519e9f883b316d86e2bb6b767a023aafd9d83\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\nceph: fix race condition validating r_parent before applying state\\n\\nAdd validation to ensure the cached parent directory inode matches the\\ndirectory info in MDS replies. This prevents client-side race conditions\\nwhere concurrent operations (e.g. rename) cause r_parent to become stale\\nbetween request initiation and reply processing, which could lead to\\napplying state changes to incorrect directory inodes.\\n\\n[ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to\\n  move CEPH_CAP_PIN reference when r_parent is updated:\\n\\n  When the parent directory lock is not held, req-\u003er_parent can become\\n  stale and is updated to point to the correct inode.  However, the\\n  associated CEPH_CAP_PIN reference was not being adjusted.  The\\n  CEPH_CAP_PIN is a reference on an inode that is tracked for\\n  accounting purposes.  Moving this pin is important to keep the\\n  accounting balanced. When the pin was not moved from the old parent\\n  to the new one, it created two problems: The reference on the old,\\n  stale parent was never released, causing a reference leak.\\n  A reference for the new parent was never acquired, creating the risk\\n  of a reference underflow later in ceph_mdsc_release_request().  This\\n  patch corrects the logic by releasing the pin from the old parent and\\n  acquiring it for the new parent when r_parent is switched.  This\\n  ensures reference accounting stays balanced. ]\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.12.48\", \"versionStartIncluding\": \"2.6.34\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.16.8\", \"versionStartIncluding\": \"2.6.34\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.17\", \"versionStartIncluding\": \"2.6.34\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2026-07-30T05:58:29.682Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2025-39927\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-30T05:58:29.682Z\", \"dateReserved\": \"2025-04-16T07:20:57.147Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2025-10-01T08:07:14.595Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.