Vulnerability-Lookup

FKIE_CVE-2026-89545

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-21 14:17

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: sunrpc: defer rq_argp and rq_resp free until after RCU grace period svc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously via kfree(), but defers the rqstp struct free via kfree_rcu(). After svc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is a window where RCU readers that started before list_del_rcu() can still traverse the thread list and find the rqstp. These readers (e.g. nfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has already been freed — a use-after-free. Fix this by moving the kfree of rq_argp and rq_resp into an explicit call_rcu() callback alongside the struct free. Resources not accessed by RCU readers (bvec, buffer pages, scratch folio, auth_data) remain synchronously freed.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/08bc49e0541260bf294962cf889a32a2d2713ad6
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0ea49d69aa806008b2424c8cf21cf746b9963967
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/c479bde671cbe2f9e152834a8b0eb7c3c295bbaf
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/svc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0ea49d69aa806008b2424c8cf21cf746b9963967",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            },
            {
              "lessThan": "08bc49e0541260bf294962cf889a32a2d2713ad6",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            },
            {
              "lessThan": "e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            },
            {
              "lessThan": "c479bde671cbe2f9e152834a8b0eb7c3c295bbaf",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/svc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.19"
            },
            {
              "lessThan": "3.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: defer rq_argp and rq_resp free until after RCU grace period\n\nsvc_rqst_free() frees rqstp-\u003erq_argp and rqstp-\u003erq_resp synchronously\nvia kfree(), but defers the rqstp struct free via kfree_rcu().  After\nsvc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is\na window where RCU readers that started before list_del_rcu() can still\ntraverse the thread list and find the rqstp.  These readers (e.g.\nnfsd_nl_rpc_status_get_dumpit()) dereference rqstp-\u003erq_argp, which has\nalready been freed \u2014 a use-after-free.\n\nFix this by moving the kfree of rq_argp and rq_resp into an explicit\ncall_rcu() callback alongside the struct free.  Resources not accessed\nby RCU readers (bvec, buffer pages, scratch folio, auth_data) remain\nsynchronously freed."
    }
  ],
  "id": "CVE-2026-89545",
  "lastModified": "2026-09-21T14:17:23.150",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:37.840",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/08bc49e0541260bf294962cf889a32a2d2713ad6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0ea49d69aa806008b2424c8cf21cf746b9963967"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c479bde671cbe2f9e152834a8b0eb7c3c295bbaf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89545 (GCVE-0-2026-89545)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:44 – Updated: 2026-09-21 13:14

Title

sunrpc: defer rq_argp and rq_resp free until after RCU grace period

Summary

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

References

4 references

URL	Tags
https://git.kernel.org/stable/c/0ea49d69aa806008b…
https://git.kernel.org/stable/c/08bc49e0541260bf2…
https://git.kernel.org/stable/c/e0c5693d3f9a5d491…
https://git.kernel.org/stable/c/c479bde671cbe2f9e…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 812443865c5fc255363d4a684a62c086af1addca , < 0ea49d69aa806008b2424c8cf21cf746b9963967 (git) Affected: 812443865c5fc255363d4a684a62c086af1addca , < 08bc49e0541260bf294962cf889a32a2d2713ad6 (git) Affected: 812443865c5fc255363d4a684a62c086af1addca , < e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090 (git) Affected: 812443865c5fc255363d4a684a62c086af1addca , < c479bde671cbe2f9e152834a8b0eb7c3c295bbaf (git)
Linux	Linux	Affected: 3.19 Unaffected: 0 , < 3.19 (semver) Unaffected: 6.12.111 , ≤ 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)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/svc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0ea49d69aa806008b2424c8cf21cf746b9963967",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            },
            {
              "lessThan": "08bc49e0541260bf294962cf889a32a2d2713ad6",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            },
            {
              "lessThan": "e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            },
            {
              "lessThan": "c479bde671cbe2f9e152834a8b0eb7c3c295bbaf",
              "status": "affected",
              "version": "812443865c5fc255363d4a684a62c086af1addca",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/svc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.19"
            },
            {
              "lessThan": "3.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "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": "6.12.111",
                  "versionStartIncluding": "3.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "3.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "3.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "3.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: defer rq_argp and rq_resp free until after RCU grace period\n\nsvc_rqst_free() frees rqstp-\u003erq_argp and rqstp-\u003erq_resp synchronously\nvia kfree(), but defers the rqstp struct free via kfree_rcu().  After\nsvc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is\na window where RCU readers that started before list_del_rcu() can still\ntraverse the thread list and find the rqstp.  These readers (e.g.\nnfsd_nl_rpc_status_get_dumpit()) dereference rqstp-\u003erq_argp, which has\nalready been freed \u2014 a use-after-free.\n\nFix this by moving the kfree of rq_argp and rq_resp into an explicit\ncall_rcu() callback alongside the struct free.  Resources not accessed\nby RCU readers (bvec, buffer pages, scratch folio, auth_data) remain\nsynchronously freed."
        }
      ],
      "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 use-after-free is reached by NFSD_CMD_RPC_STATUS_GET, a generic-netlink dump over AF_NETLINK that walks svc_rqst threads and reads rq_argp; remote NFS RPCs never enter nfsd_nl_rpc_status_get_dumpit().\nAC:L - The attacker fully controls the dumpit reader and can loop it while nfsd threads exit (dynamic idle-timeout kills or thread-count changes), and can further churn threads with NFS traffic; this is an attacker-driven RCU race, not a condition beyond their control.\nPR:L - NFSD_CMD_RPC_STATUS_GET is registered with GENL_CMD_CAP_DUMP and no GENL_ADMIN_PERM, so any unprivileged process in the nfsd network namespace can invoke the dump; exploiting it does not require CAP_NET_ADMIN or root.\nUI:N - The attacker issues the netlink dump themselves; no separate victim action such as mounting a filesystem or opening a device is required.\nS:U - This is a kernel-heap use-after-free in sunrpc/nfsd on the local host; impact stays inside the kernel\u0027s security authority and does not cross a VM, IOMMU, or other security boundary.\nC:H - dumpit dereferences the kfree\u0027d rq_argp (nfsd4_compoundargs) and reads opcnt/opnums under rcu_read_lock; a kernel UAF with heap reuse of that object yields an arbitrary read primitive.\nI:H - The same slab UAF is heap-sprayable so a replaced rq_argp can make dumpit walk attacker-controlled args-\u003eops[], enabling kernel memory corruption and control-flow hijacking.\nA:H - Use-after-free of rq_argp while an RCU reader still holds the svc_rqst from sp_all_threads can oops or panic the kernel even if the UAF is not fully turned into code execution."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-21T13:14:26.005Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0ea49d69aa806008b2424c8cf21cf746b9963967"
        },
        {
          "url": "https://git.kernel.org/stable/c/08bc49e0541260bf294962cf889a32a2d2713ad6"
        },
        {
          "url": "https://git.kernel.org/stable/c/e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090"
        },
        {
          "url": "https://git.kernel.org/stable/c/c479bde671cbe2f9e152834a8b0eb7c3c295bbaf"
        }
      ],
      "title": "sunrpc: defer rq_argp and rq_resp free until after RCU grace period",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89545",
    "datePublished": "2026-09-11T19:44:21.161Z",
    "dateReserved": "2026-09-11T19:38:34.722Z",
    "dateUpdated": "2026-09-21T13:14:26.005Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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FKIE_CVE-2026-89545

CVE-2026-89545 (GCVE-0-2026-89545)

Tags

Sightings

Nomenclature

Related by attack behaviour