Vulnerability-Lookup

GHSA-4RJJ-PGM8-M2R9

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-13 09:32

Details

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

svcrdma: Reject Read lists that exceed the page budget

Individual Read segment lengths are validated at decode time, but nothing prevents a requester from sending multiple segments whose cumulative length exceeds the rq_pages array budget. When one segment fills the page array exactly, the runtime guard in svc_rdma_build_read_segment() is bypassed because len reaches zero. A subsequent segment then accesses the NULL sentinel slot at rq_pages[rq_maxpages], resulting in a NULL pointer dereference during DMA mapping.

Accumulate pages across all Read segments and reject the message at decode time when the total would overflow the page budget.

Severity

7.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89528"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:35Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject Read lists that exceed the page budget\n\nIndividual Read segment lengths are validated at decode time, but\nnothing prevents a requester from sending multiple segments whose\ncumulative length exceeds the rq_pages array budget. When one\nsegment fills the page array exactly, the runtime guard in\nsvc_rdma_build_read_segment() is bypassed because len reaches zero.\nA subsequent segment then accesses the NULL sentinel slot at\nrq_pages[rq_maxpages], resulting in a NULL pointer dereference during\nDMA mapping.\n\nAccumulate pages across all Read segments and reject the message at\ndecode time when the total would overflow the page budget.",
  "id": "GHSA-4rjj-pgm8-m2r9",
  "modified": "2026-09-13T09:32:17Z",
  "published": "2026-09-11T21:31:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89528"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0ca487abb3bdf581851664b5db21f364caf57682"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1a3af2262cb384112ef38632de4690682be528b4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/465f511f59a0fa7a80d5d1073c4b24f28ea38f58"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-89528 (GCVE-0-2026-89528)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:44 – Updated: 2026-09-13 06:30

Title

svcrdma: Reject Read lists that exceed the page budget

Summary

In the Linux kernel, the following vulnerability has been resolved: svcrdma: Reject Read lists that exceed the page budget Individual Read segment lengths are validated at decode time, but nothing prevents a requester from sending multiple segments whose cumulative length exceeds the rq_pages array budget. When one segment fills the page array exactly, the runtime guard in svc_rdma_build_read_segment() is bypassed because len reaches zero. A subsequent segment then accesses the NULL sentinel slot at rq_pages[rq_maxpages], resulting in a NULL pointer dereference during DMA mapping. Accumulate pages across all Read segments and reject the message at decode time when the total would overflow the page budget.

Severity

7.5 (High)


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

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/1a3af2262cb384112…
https://git.kernel.org/stable/c/465f511f59a0fa7a8…
https://git.kernel.org/stable/c/0ca487abb3bdf5818…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 026d958b38c628a1b4ced534808945365e2747a5 , < 1a3af2262cb384112ef38632de4690682be528b4 (git) Affected: 026d958b38c628a1b4ced534808945365e2747a5 , < 465f511f59a0fa7a80d5d1073c4b24f28ea38f58 (git) Affected: 026d958b38c628a1b4ced534808945365e2747a5 , < 0ca487abb3bdf581851664b5db21f364caf57682 (git)
Linux	Linux	Affected: 4.13 Unaffected: 0 , < 4.13 (semver) Unaffected: 6.18.51 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/xprtrdma/svc_rdma_recvfrom.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1a3af2262cb384112ef38632de4690682be528b4",
              "status": "affected",
              "version": "026d958b38c628a1b4ced534808945365e2747a5",
              "versionType": "git"
            },
            {
              "lessThan": "465f511f59a0fa7a80d5d1073c4b24f28ea38f58",
              "status": "affected",
              "version": "026d958b38c628a1b4ced534808945365e2747a5",
              "versionType": "git"
            },
            {
              "lessThan": "0ca487abb3bdf581851664b5db21f364caf57682",
              "status": "affected",
              "version": "026d958b38c628a1b4ced534808945365e2747a5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/xprtrdma/svc_rdma_recvfrom.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.13"
            },
            {
              "lessThan": "4.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "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": "6.18.51",
                  "versionStartIncluding": "4.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "4.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "4.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject Read lists that exceed the page budget\n\nIndividual Read segment lengths are validated at decode time, but\nnothing prevents a requester from sending multiple segments whose\ncumulative length exceeds the rq_pages array budget. When one\nsegment fills the page array exactly, the runtime guard in\nsvc_rdma_build_read_segment() is bypassed because len reaches zero.\nA subsequent segment then accesses the NULL sentinel slot at\nrq_pages[rq_maxpages], resulting in a NULL pointer dereference during\nDMA mapping.\n\nAccumulate pages across all Read segments and reject the message at\ndecode time when the total would overflow the page budget."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - svcrdma is nfsd\u0027s RPC-over-RDMA server transport; a remote peer reaches svc_rdma_recvfrom() by sending a Call with a Read list on an enabled NFS/RDMA listener over routable RoCEv2 or iWARP.\nAC:L - The attacker fully controls Read-segment lengths in the transport header and can deterministically fill rq_pages exactly, then send a further segment so the len==0 overrun guard is skipped and the NULL sentinel is DMA-mapped, with no race or uncontrollable layout.\nPR:N - xdr_count_read_segments() and svc_rdma_build_read_segment() run in svc_rdma_recvfrom() while assembling the transport message, before svc_process() performs RPC or NFS authentication, and RDMA CM accept has no credential check.\nUI:N - Sending a crafted RPC-over-RDMA message with an over-budget Read list is sufficient; no victim mount, click, or other user action is required.\nS:U - The NULL dereference oops stays in the host kernel that owns nfsd/svcrdma; this is not a VM, IOMMU, or sandbox escape.\nC:N - The fault is a NULL pointer dereference of the rq_pages[rq_maxpages] sentinel during DMA mapping; the access faults immediately and does not disclose kernel memory.\nI:N - The sentinel slot is a guaranteed NULL page pointer, not an out-of-bounds page used as a write destination; DMA mapping aborts on the NULL page without an arbitrary-write or control-flow hijack primitive.\nA:H - DMA mapping the NULL sentinel produces a kernel oops or panic that an unauthenticated NFS/RDMA peer can trigger repeatedly."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-13T06:30:25.969Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
          "url": "https://git.kernel.org/stable/c/465f511f59a0fa7a80d5d1073c4b24f28ea38f58"
        },
        {
          "url": "https://git.kernel.org/stable/c/0ca487abb3bdf581851664b5db21f364caf57682"
        }
      ],
      "title": "svcrdma: Reject Read lists that exceed the page budget",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89528",
    "datePublished": "2026-09-11T19:44:08.514Z",
    "dateReserved": "2026-09-11T19:38:34.719Z",
    "dateUpdated": "2026-09-13T06:30:25.969Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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