Vulnerability-Lookup

FKIE_CVE-2026-89530

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-13 07:17

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: svcrdma: Reject inline replies that overflow the pull-up buffer An RPC-over-RDMA client can request a reply, such as an NFS READ payload, without providing a Write list or a Reply chunk to carry it. When such a reply needs more scatter/gather entries than the device's Send Queue supports, svc_rdma_pull_up_needed() selects pull-up and svc_rdma_pull_up_reply_msg() linearizes the whole reply into sctxt->sc_xprt_buf. That buffer is only sc_max_req_size bytes, while the reply on this path is bounded only by the client's request, so svc_rdma_xb_linearize() copies past the end of the buffer and corrupts adjacent slab memory. The oversized length is then stored in sc_sges[0].length and posted, so the device also reads beyond the mapped region. The SGE-exhaustion branch is the only pull-up path that can exceed the buffer: the threshold branch pulls up only replies smaller than RPCRDMA_PULLUP_THRESH, and replies that fit the device's SGE budget are sent directly without linearization. Make svc_rdma_pull_up_needed() report -E2BIG when the reply it would pull up cannot fit sc_max_req_size, and fail the request with ERR_CHUNK as RFC 8166 Section 4.5.3 directs rather than dropping the connection. The helper no longer answers a simple yes/no question: it now reports pull-up, no pull-up, or -E2BIG for a reply too large to linearize. Rename svc_rdma_pull_up_needed() to svc_rdma_check_pull_up() so its name no longer implies a boolean predicate.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0fbe20dfe74b783d255bf389a6ea77aa25dc7860
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/1949dd1576f7a8aa161b1330c6125df9d53046d5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fcd91b9957462d398792201c239dffaeff1cc8b2

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/xprtrdma/svc_rdma_sendto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fcd91b9957462d398792201c239dffaeff1cc8b2",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "lessThan": "1949dd1576f7a8aa161b1330c6125df9d53046d5",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "lessThan": "8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "lessThan": "0fbe20dfe74b783d255bf389a6ea77aa25dc7860",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9b65b18f817d9ada2bf67351f24bdcce6789a0bb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d564356e1919d1178568c19af410cfc1a9076663",
              "versionType": "git"
            },
            {
              "lessThan": "4.20",
              "status": "affected",
              "version": "4.19.22",
              "versionType": "semver"
            },
            {
              "lessThan": "4.21",
              "status": "affected",
              "version": "4.20.9",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/xprtrdma/svc_rdma_sendto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "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\nsvcrdma: Reject inline replies that overflow the pull-up buffer\n\nAn RPC-over-RDMA client can request a reply, such as an NFS READ\npayload, without providing a Write list or a Reply chunk to carry\nit. When such a reply needs more scatter/gather entries than the\ndevice\u0027s Send Queue supports, svc_rdma_pull_up_needed() selects\npull-up and svc_rdma_pull_up_reply_msg() linearizes the whole\nreply into sctxt-\u003esc_xprt_buf. That buffer is only sc_max_req_size\nbytes, while the reply on this path is bounded only by the client\u0027s\nrequest, so svc_rdma_xb_linearize() copies past the end of the\nbuffer and corrupts adjacent slab memory. The oversized length is\nthen stored in sc_sges[0].length and posted, so the device also\nreads beyond the mapped region.\n\nThe SGE-exhaustion branch is the only pull-up path that can exceed\nthe buffer: the threshold branch pulls up only replies smaller\nthan RPCRDMA_PULLUP_THRESH, and replies that fit the device\u0027s SGE\nbudget are sent directly without linearization. Make\nsvc_rdma_pull_up_needed() report -E2BIG when the reply it would\npull up cannot fit sc_max_req_size, and fail the request with\nERR_CHUNK as RFC 8166 Section 4.5.3 directs rather than dropping\nthe connection.\n\nThe helper no longer answers a simple yes/no question: it now\nreports pull-up, no pull-up, or -E2BIG for a reply too large to\nlinearize. Rename svc_rdma_pull_up_needed() to\nsvc_rdma_check_pull_up() so its name no longer implies a boolean\npredicate."
    }
  ],
  "id": "CVE-2026-89530",
  "lastModified": "2026-09-13T07:17:15.237",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:35.850",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0fbe20dfe74b783d255bf389a6ea77aa25dc7860"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1949dd1576f7a8aa161b1330c6125df9d53046d5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fcd91b9957462d398792201c239dffaeff1cc8b2"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89530 (GCVE-0-2026-89530)

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

Title

svcrdma: Reject inline replies that overflow the pull-up buffer

Summary

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/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/fcd91b9957462d398…
https://git.kernel.org/stable/c/1949dd1576f7a8aa1…
https://git.kernel.org/stable/c/8ec60eb51fae37cd3…
https://git.kernel.org/stable/c/0fbe20dfe74b783d2…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e248aa7be86e8179f20ac0931774ecd746f3f5bf , < fcd91b9957462d398792201c239dffaeff1cc8b2 (git) Affected: e248aa7be86e8179f20ac0931774ecd746f3f5bf , < 1949dd1576f7a8aa161b1330c6125df9d53046d5 (git) Affected: e248aa7be86e8179f20ac0931774ecd746f3f5bf , < 8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf (git) Affected: e248aa7be86e8179f20ac0931774ecd746f3f5bf , < 0fbe20dfe74b783d255bf389a6ea77aa25dc7860 (git) Affected: 9b65b18f817d9ada2bf67351f24bdcce6789a0bb (git) Affected: d564356e1919d1178568c19af410cfc1a9076663 (git) Affected: 4.19.22 , < 4.20 (semver) Affected: 4.20.9 , < 4.21 (semver)
Linux	Linux	Affected: 5.0 Unaffected: 0 , < 5.0 (semver) Unaffected: 6.12.109 , ≤ 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/xprtrdma/svc_rdma_sendto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fcd91b9957462d398792201c239dffaeff1cc8b2",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "lessThan": "1949dd1576f7a8aa161b1330c6125df9d53046d5",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "lessThan": "8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "lessThan": "0fbe20dfe74b783d255bf389a6ea77aa25dc7860",
              "status": "affected",
              "version": "e248aa7be86e8179f20ac0931774ecd746f3f5bf",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9b65b18f817d9ada2bf67351f24bdcce6789a0bb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d564356e1919d1178568c19af410cfc1a9076663",
              "versionType": "git"
            },
            {
              "lessThan": "4.20",
              "status": "affected",
              "version": "4.19.22",
              "versionType": "semver"
            },
            {
              "lessThan": "4.21",
              "status": "affected",
              "version": "4.20.9",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/xprtrdma/svc_rdma_sendto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "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": "6.12.109",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.19.22",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.20.9",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject inline replies that overflow the pull-up buffer\n\nAn RPC-over-RDMA client can request a reply, such as an NFS READ\npayload, without providing a Write list or a Reply chunk to carry\nit. When such a reply needs more scatter/gather entries than the\ndevice\u0027s Send Queue supports, svc_rdma_pull_up_needed() selects\npull-up and svc_rdma_pull_up_reply_msg() linearizes the whole\nreply into sctxt-\u003esc_xprt_buf. That buffer is only sc_max_req_size\nbytes, while the reply on this path is bounded only by the client\u0027s\nrequest, so svc_rdma_xb_linearize() copies past the end of the\nbuffer and corrupts adjacent slab memory. The oversized length is\nthen stored in sc_sges[0].length and posted, so the device also\nreads beyond the mapped region.\n\nThe SGE-exhaustion branch is the only pull-up path that can exceed\nthe buffer: the threshold branch pulls up only replies smaller\nthan RPCRDMA_PULLUP_THRESH, and replies that fit the device\u0027s SGE\nbudget are sent directly without linearization. Make\nsvc_rdma_pull_up_needed() report -E2BIG when the reply it would\npull up cannot fit sc_max_req_size, and fail the request with\nERR_CHUNK as RFC 8166 Section 4.5.3 directs rather than dropping\nthe connection.\n\nThe helper no longer answers a simple yes/no question: it now\nreports pull-up, no pull-up, or -E2BIG for a reply too large to\nlinearize. Rename svc_rdma_pull_up_needed() to\nsvc_rdma_check_pull_up() so its name no longer implies a boolean\npredicate."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - svcrdma is nfsd\u0027s RPC-over-RDMA server transport; a remote NFS/RDMA client reaches svc_rdma_sendto over InfiniBand, RoCE, or iWARP, including IP-routable RoCEv2/iWARP and Soft-RoCE, so this is a network attack.\nAC:L - The attacker fully controls omitting the Write list and Reply chunk and the NFS READ size; with the default 4096-byte pull-up buffer and ~5 Send SGEs, a multi-page inline READ deterministically takes the SGE-exhaustion pull-up path and overflows, with no race or uncontrollable layout.\nPR:N - RDMA-CM accept has no credential check, and AUTH_NULL/AUTH_UNIX need no real account; default NFS exports accept those flavors, so a fabric peer can drive a large READ reply without local or init-namespace privileges.\nUI:N - Exploitation requires only attacker-sent RPC-over-RDMA Calls that elicit a large inline reply; no victim mount, click, or other user action is needed beyond nfsd already listening on RDMA.\nS:U - The kmalloc overflow and oversized RDMA Send stay inside the host kernel\u0027s security authority; this is not a VM, IOMMU, or sandbox escape.\nC:H - svc_rdma_xb_linearize() copies past kmalloc sc_xprt_buf, then the inflated sc_sges[0].length is posted with the PD local DMA lkey, so the device reads adjacent kernel memory onto the wire; the heap smash is also leveragable for disclosure.\nI:H - The unbounded memcpy is a heap out-of-bounds write of attacker-influenced NFS READ payload into adjacent slab objects, enabling corruption of neighboring kernel state and control-flow hijacking.\nA:H - Overflowing a 4KB send buffer by up to the NFS/RDMA max payload smashes adjacent slab and can oops or panic, and posting an SGE longer than the DMA mapping can also fault the device or kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-13T06:30:27.209Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/fcd91b9957462d398792201c239dffaeff1cc8b2"
        },
        {
          "url": "https://git.kernel.org/stable/c/1949dd1576f7a8aa161b1330c6125df9d53046d5"
        },
        {
          "url": "https://git.kernel.org/stable/c/8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf"
        },
        {
          "url": "https://git.kernel.org/stable/c/0fbe20dfe74b783d255bf389a6ea77aa25dc7860"
        }
      ],
      "title": "svcrdma: Reject inline replies that overflow the pull-up buffer",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89530",
    "datePublished": "2026-09-11T19:44:10.024Z",
    "dateReserved": "2026-09-11T19:38:34.719Z",
    "dateUpdated": "2026-09-13T06:30:27.209Z",
    "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.

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.