CVE-2026-64102

Estado: AnalizadaCrítica (9.8)—

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

RDMA/siw: Reject MPA FPDU length underflow before signed receive math

A malicious connected siw peer can send an iWARP FPDU whose MPA length field (c_hdr->mpa_len, 16 bit big-endian, peer-controlled) is smaller than the fixed DDP/RDMAP header for the announced opcode. Soft-iWARP parses the full header in siw_get_hdr() based on iwarp_pktinfo[opcode] .hdr_len, but never compares mpa_len against that header length.

siw_tcp_rx_data() then derives

where fpdu_part_rcvd equals iwarp_pktinfo[opcode].hdr_len at this point. For a tagged WRITE (hdr_len 16, MPA_HDR_SIZE 2) the smallest on-wire mpa_len of 0 yields fpdu_part_rem = -14, and any mpa_len below hdr_len - MPA_HDR_SIZE underflows to a negative int.

Leer descripción completaMostrar menos

The signed value then flows into siw_proc_write()/siw_proc_rresp() as

is handed to siw_check_mem() as an int len (whose interval check addr + len > mem->va + mem->len is satisfied for a valid base when len is negative), and reaches siw_rx_data() -> siw_rx_kva() / siw_rx_umem() -> skb_copy_bits() as a signed copy length. The header copy branch in skb_copy_bits() promotes that to size_t, producing a multi-gigabyte read.

KASAN under a KUnit harness that drives the real kernel TCP receive path -- a loopback AF_INET socketpair, the malformed FPDU written via kernel_sendmsg, sk_data_ready firing in softirq, tcp_read_sock dispatching to siw_tcp_rx_data -- reports:

Add the missing invariant at the earliest point where the peer header is fully assembled. iwarp_pktinfo[*].hdr_len - MPA_HDR_SIZE is exactly the value the siw transmitter uses as the minimum mpa_len for each opcode (drivers/infiniband/sw/siw/siw_qp.c:33), so this matches the protocol contract. Out-of-range FPDUs terminate the connection with TERM_ERROR_LAYER_LLP / LLP_ETYPE_MPA / LLP_ECODE_FPDU_START -- which is RFC 5044 Section 8 error code 3 ("Marker and ULPDU Length fields do not agree on the start of an FPDU"), the correct framing-error class for this inconsistency.

Detalles técnicos trazas, registros y código del informe original

    srx->fpdu_part_rem = be16_to_cpu(mpa_len) - fpdu_part_rcvd
                         + MPA_HDR_SIZE;

    bytes = min(srx->fpdu_part_rem, srx->skb_new);

    BUG: KASAN: use-after-free in skb_copy_bits+0x284/0x480
    Read of size 4294967295 at addr ffff888...
    Call Trace:
     skb_copy_bits
     siw_rx_kva
     siw_rx_data
     siw_check_mem
     siw_proc_write
     siw_tcp_rx_data
     __tcp_read_sock
     siw_qp_llp_data_ready
     tcp_data_ready
     tcp_data_queue

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 9.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.50%
Percentil entre todas las CVEs puntuadas: 41
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access85 %
Impacto secundarioT1499.004 Application or System Exploitationimpact65 %

Vulnerabilidad de kernel Linux (AV:N, PR:N) explotable remotamente sin interacción. El underflow de enteros permite leer memoria arbitraria (KASAN) y DoS por consumo de recursos (lectura de multi-gigabytes). Impacto primario conforme a pista; DoS secundario por la KASAN y lectura masiva.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application Isolation and Sandboxing

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-125

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-64102",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "683f7cfbf514193d63c0efa079f3352bde84c2e0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "4a331582011d9e8089af8aa2a61ec6b4443bb245",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "33a8b5e971e294ec2a7b74211c545e09efd8e9ac",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "14553be882d9ce91749c9d64041de66e34ad8e70",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "c7c0c0f4379dedec12d24dbb9dded5d2db7fd9f2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "1012896f4225e8f801ff3c1648023845b66dfb11",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "775b4dc9618a99a1fa48b57554041a5dc17e1336",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b6a361b8c482f22ac99c3273285ff16b23fba91",
              "lessThan": "0ce1bc9e46ecabe84772bb561e373c0d9876d6f2",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/infiniband/sw/siw/siw_qp_rx.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.3"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.3",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.258",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.209",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.142",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.92",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/infiniband/sw/siw/siw_qp_rx.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-07-19T16:17:51.383",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0ce1bc9e46ecabe84772bb561e373c0d9876d6f2",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/1012896f4225e8f801ff3c1648023845b66dfb11",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/14553be882d9ce91749c9d64041de66e34ad8e70",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/33a8b5e971e294ec2a7b74211c545e09efd8e9ac",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4a331582011d9e8089af8aa2a61ec6b4443bb245",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/683f7cfbf514193d63c0efa079f3352bde84c2e0",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/775b4dc9618a99a1fa48b57554041a5dc17e1336",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c7c0c0f4379dedec12d24dbb9dded5d2db7fd9f2",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/siw: Reject MPA FPDU length underflow before signed receive math\n\nA malicious connected siw peer can send an iWARP FPDU whose MPA length\nfield (c_hdr->mpa_len, 16 bit big-endian, peer-controlled) is smaller\nthan the fixed DDP/RDMAP header for the announced opcode. Soft-iWARP\nparses the full header in siw_get_hdr() based on iwarp_pktinfo[opcode]\n.hdr_len, but never compares mpa_len against that header length.\n\nsiw_tcp_rx_data() then derives\n\n    srx->fpdu_part_rem = be16_to_cpu(mpa_len) - fpdu_part_rcvd\n                         + MPA_HDR_SIZE;\n\nwhere fpdu_part_rcvd equals iwarp_pktinfo[opcode].hdr_len at this\npoint. For a tagged WRITE (hdr_len 16, MPA_HDR_SIZE 2) the smallest\non-wire mpa_len of 0 yields fpdu_part_rem = -14, and any mpa_len below\nhdr_len - MPA_HDR_SIZE underflows to a negative int.\n\nThe signed value then flows into siw_proc_write()/siw_proc_rresp() as\n\n    bytes = min(srx->fpdu_part_rem, srx->skb_new);\n\nis handed to siw_check_mem() as an int len (whose interval check\naddr + len > mem->va + mem->len is satisfied for a valid base when\nlen is negative), and reaches siw_rx_data() -> siw_rx_kva() /\nsiw_rx_umem() -> skb_copy_bits() as a signed copy length. The header\ncopy branch in skb_copy_bits() promotes that to size_t, producing a\nmulti-gigabyte read.\n\nKASAN under a KUnit harness that drives the real kernel TCP receive\npath -- a loopback AF_INET socketpair, the malformed FPDU written via\nkernel_sendmsg, sk_data_ready firing in softirq, tcp_read_sock\ndispatching to siw_tcp_rx_data -- reports:\n\n    BUG: KASAN: use-after-free in skb_copy_bits+0x284/0x480\n    Read of size 4294967295 at addr ffff888...\n    Call Trace:\n     skb_copy_bits\n     siw_rx_kva\n     siw_rx_data\n     siw_check_mem\n     siw_proc_write\n     siw_tcp_rx_data\n     __tcp_read_sock\n     siw_qp_llp_data_ready\n     tcp_data_ready\n     tcp_data_queue\n\nAdd the missing invariant at the earliest point where the peer header\nis fully assembled. iwarp_pktinfo[*].hdr_len - MPA_HDR_SIZE is exactly\nthe value the siw transmitter uses as the minimum mpa_len for each\nopcode (drivers/infiniband/sw/siw/siw_qp.c:33), so this matches the\nprotocol contract. Out-of-range FPDUs terminate the connection with\nTERM_ERROR_LAYER_LLP / LLP_ETYPE_MPA / LLP_ECODE_FPDU_START -- which\nis RFC 5044 Section 8 error code 3 (\"Marker and ULPDU Length fields\ndo not agree on the start of an FPDU\"), the correct framing-error\nclass for this inconsistency."
    }
  ],
  "lastModified": "2026-08-12T15:49:23.140",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "24B3A7BD-AD4C-4029-A7C0-87FA0CB1BFEB",
              "versionEndExcluding": "5.10.258",
              "versionStartIncluding": "5.3"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "919C10A9-7951-4A74-BADD-C135A0A8D8B4",
              "versionEndExcluding": "5.15.209",
              "versionStartIncluding": "5.11"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "92385813-D91D-480D-83A1-F423D2CBB2BA",
              "versionEndExcluding": "6.1.175",
              "versionStartIncluding": "5.16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "FBFF77B0-526A-4AF1-84D0-ED7187624A67",
              "versionEndExcluding": "6.6.142",
              "versionStartIncluding": "6.2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9CB90BD9-95B7-4D7F-9F17-4ECE6CFB66C9",
              "versionEndExcluding": "6.12.92",
              "versionStartIncluding": "6.7"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A4B1EF6D-18D7-4838-BC37-7499D5DCC3C0",
              "versionEndExcluding": "6.18.34",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0520D091-FC52-4A50-AF07-70AE7D08B750",
              "versionEndExcluding": "7.0.11",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}