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GHSA-4C5J-JGFR-26GP

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

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

afs: Fix lack of locking around modifications of net->cells_dyn_ino

Fix the lack of locking around modifications of net->cells_dyn_ino by taking net->cells_lock exclusively. This also requires to cell to be removed from net->cells_dyn_ino in afs_destroy_cell_work() rather than in afs_cell_destroy() as the latter runs in RCU cleanup context and sleeping locks cannot be taken there.

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-2026-72372"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:10Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nafs: Fix lack of locking around modifications of net-\u003ecells_dyn_ino\n\nFix the lack of locking around modifications of net-\u003ecells_dyn_ino by\ntaking net-\u003ecells_lock exclusively.  This also requires to cell to be\nremoved from net-\u003ecells_dyn_ino in afs_destroy_cell_work() rather than in\nafs_cell_destroy() as the latter runs in RCU cleanup context and sleeping\nlocks cannot be taken there.",
  "id": "GHSA-4c5j-jgfr-26gp",
  "modified": "2026-08-17T06:33:26Z",
  "published": "2026-08-15T06:32:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72372"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2ffb70a8a01988046bb207b7d0af9358a8337378"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4d8a2fe8847859f4fa4e9a2fa1221c9c1158e66b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55e841836c6f4646490f7b0347192b7a92d431ba"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e94f92fd56c553a8bf9421c3289e1b85c7c08857"
    }
  ],
  "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-2026-72372 (GCVE-0-2026-72372)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:56 – Updated: 2026-08-17 05:43

Title

afs: Fix lack of locking around modifications of net->cells_dyn_ino

Summary

In the Linux kernel, the following vulnerability has been resolved: afs: Fix lack of locking around modifications of net->cells_dyn_ino Fix the lack of locking around modifications of net->cells_dyn_ino by taking net->cells_lock exclusively. This also requires to cell to be removed from net->cells_dyn_ino in afs_destroy_cell_work() rather than in afs_cell_destroy() as the latter runs in RCU cleanup context and sleeping locks cannot be taken there.

Severity

7.8 (High)


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

Assigner

Linux mitre root Scorecard

References

4 references

URL	Tags
https://git.kernel.org/stable/c/4d8a2fe8847859f4f…
https://git.kernel.org/stable/c/2ffb70a8a01988046…
https://git.kernel.org/stable/c/e94f92fd56c553a8b…
https://git.kernel.org/stable/c/55e841836c6f46464…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 537b0105952578531f748c7fb3ce36ae9a514784 , < 4d8a2fe8847859f4fa4e9a2fa1221c9c1158e66b (git) Affected: 1d0b929fc070b4115403a0a6206a0c6a62dd61f5 , < 2ffb70a8a01988046bb207b7d0af9358a8337378 (git) Affected: 1d0b929fc070b4115403a0a6206a0c6a62dd61f5 , < e94f92fd56c553a8bf9421c3289e1b85c7c08857 (git) Affected: 1d0b929fc070b4115403a0a6206a0c6a62dd61f5 , < 55e841836c6f4646490f7b0347192b7a92d431ba (git) Affected: 6.12.97 , < 6.12.101 (semver)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/afs/cell.c",
            "fs/afs/dynroot.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4d8a2fe8847859f4fa4e9a2fa1221c9c1158e66b",
              "status": "affected",
              "version": "537b0105952578531f748c7fb3ce36ae9a514784",
              "versionType": "git"
            },
            {
              "lessThan": "2ffb70a8a01988046bb207b7d0af9358a8337378",
              "status": "affected",
              "version": "1d0b929fc070b4115403a0a6206a0c6a62dd61f5",
              "versionType": "git"
            },
            {
              "lessThan": "e94f92fd56c553a8bf9421c3289e1b85c7c08857",
              "status": "affected",
              "version": "1d0b929fc070b4115403a0a6206a0c6a62dd61f5",
              "versionType": "git"
            },
            {
              "lessThan": "55e841836c6f4646490f7b0347192b7a92d431ba",
              "status": "affected",
              "version": "1d0b929fc070b4115403a0a6206a0c6a62dd61f5",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.101",
              "status": "affected",
              "version": "6.12.97",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/afs/cell.c",
            "fs/afs/dynroot.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "6.12.97",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nafs: Fix lack of locking around modifications of net-\u003ecells_dyn_ino\n\nFix the lack of locking around modifications of net-\u003ecells_dyn_ino by\ntaking net-\u003ecells_lock exclusively.  This also requires to cell to be\nremoved from net-\u003ecells_dyn_ino in afs_destroy_cell_work() rather than in\nafs_cell_destroy() as the latter runs in RCU cleanup context and sleeping\nlocks cannot be taken there."
        }
      ],
      "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 bug is reached only through local VFS operations on an AFS dynroot mount (getdents/readdir via afs_dynroot_readdir, lookup via afs_dynroot_lookup_cell) and cell create/destroy paths (afs_alloc_cell/afs_destroy_cell_work), not from remote AFS/RxRPC packet handling.\nAC:L - An attacker can reliably win the race by running concurrent threads that repeatedly readdir /afs while creating and expiring cells through lookups or /proc/net/afs/cells writes; syzbot and public PoCs reproduced the slab UAF within minutes without uncontrollable layout dependencies.\nPR:L - Exploitation requires only an unprivileged local user who can access a dynroot mount (typical world-readable /afs on AFS clients) or mount AFS with -o dyn inside a user namespace where CAP_SYS_ADMIN is available; real init-namespace root is not required.\nUI:N - No victim interaction is needed once dynroot is available; the attacker directly issues the readdir and cell-creation syscalls that race unsynchronized idr_alloc_cyclic, idr_remove, and idr_get_next on net-\u003ecells_dyn_ino.\nS:U - Impact is confined to kernel memory integrity and privilege boundaries within the host kernel; it does not cross VM, container, or IOMMU security scopes into a different authority.\nC:H - Concurrent idr_remove during afs_dynroot_readdir_cells leaves idr_get_next with a dangling afs_cell pointer, causing slab use-after-free reads of cell-\u003ename and cell-\u003estate (confirmed by KASAN in afs_dynroot_readdir) and enabling further kernel memory disclosure.\nI:H - IDR tree corruption and use-after-free of afs_cell objects provide attacker-influenced heap corruption primitives that can be developed into arbitrary kernel writes or control-flow hijack, not merely a benign error return.\nA:H - The race causes kernel oops/panic from corrupted IDR traversal or use-after-free during dir_emit; repeated triggering can crash or hang the system, satisfying high availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:43:25.401Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4d8a2fe8847859f4fa4e9a2fa1221c9c1158e66b"
        },
        {
          "url": "https://git.kernel.org/stable/c/2ffb70a8a01988046bb207b7d0af9358a8337378"
        },
        {
          "url": "https://git.kernel.org/stable/c/e94f92fd56c553a8bf9421c3289e1b85c7c08857"
        },
        {
          "url": "https://git.kernel.org/stable/c/55e841836c6f4646490f7b0347192b7a92d431ba"
        }
      ],
      "title": "afs: Fix lack of locking around modifications of net-\u003ecells_dyn_ino",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72372",
    "datePublished": "2026-08-15T05:56:07.916Z",
    "dateReserved": "2026-08-09T03:40:39.922Z",
    "dateUpdated": "2026-08-17T05:43:25.401Z",
    "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-4C5J-JGFR-26GP

CVE-2026-72372 (GCVE-0-2026-72372)

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