{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-64268",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-64268"
  ],
  "published": "2026-07-25T08:51:45Z",
  "summary": "RDMA/siw: bound Read Response placement to the RREAD length",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/siw: bound Read Response placement to the RREAD length\n\nIn drivers/infiniband/sw/siw/siw_qp_rx.c, siw_proc_rresp() places each\ninbound Read Response DDP segment at sge->laddr + wqe->processed and then\naccumulates wqe->processed, but it never checks the running total against\nthe sink buffer length on continuation segments. siw_check_sge() resolves\nand validates the sink memory only on the first fragment (the if (!*mem)\nbranch), and siw_rresp_check_ntoh() compares the cumulative length against\nwqe->bytes only on the final segment (the !frx->more_ddp_segs guard).\n\nA connected siw peer that answers an outstanding RREAD with Read Response\nsegments that keep the DDP Last flag clear, carrying more total payload\nthan the RREAD requested, drives wqe->processed past the validated sink\nbuffer; the next siw_rx_data() call writes out of bounds at\nsge->laddr + wqe->processed. siw runs iWARP over ordinary routable TCP,\nso the peer is the remote end of an established RDMA connection and needs\nno local privilege.\n\nBound every segment before placement, exactly as siw_proc_send() and\nsiw_proc_write() already do for their tagged and untagged paths, and\nterminate the connection with a base-or-bounds DDP error when the\nRead Response would overrun the sink buffer.\n\nThis is the second receive-path length fix for this file. A separate\nchange rejects an MPA FPDU length that underflows the per-fragment\nremainder in the header decode; that guard does not cover this case,\nbecause here each individual segment length is self-consistent and only\nthe accumulated placement offset overruns the buffer.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.178",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-64268"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a31b6d18ded3cc32d9ee85a6ff0726d4274887b2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/595e6537ad1a210da32cbb9a7f91aa73090915ba"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3ef7e052cbd05a8b13a51a07b185a39ec93ee1cf"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b2e26c955f8dd7e8d3f16c858db05245ea4fa817"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6bc89f34a4597f9f6d41f7a60c67a3153bfe8851"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/423a78ff7928c2601013f73ec6d896f5597d0df5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/75c93cd3c421890f49ea93f0b978b9b7bb10e5e3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7d29f7e9dbd844cae4d3e559cf78324b9642fd6b"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-17T05:24:08Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 9.8,
      "cvss_v3_severity": "Critical",
      "scenario": "AV:N - siw carries iWARP over ordinary routable TCP, and the vulnerable receive callback processes crafted Read Response FPDUs from the remote endpoint of an established RDMA connection.\nAC:L - The peer learns the sink tag, address, and length from the RREAD and can deterministically send oversized continuation segments; no race or uncontrollable condition is required.\nPR:N - The MPA/siw data path performs no credential or capability check on the connected peer, and an unauthenticated RDMA service can accept the connection and issue attacker-induced RREADs.\nUI:N - The overflow is triggered through an automated RDMA protocol exchange and requires no human action.\nS:U - The corruption compromises resources within the affected host's kernel security authority and does not inherently cross a VM, IOMMU, or other security boundary.\nC:H - The global DMA/KVA sink case exposes the sink address and permits attacker-controlled kernel memory corruption, which can enable control-flow hijacking and arbitrary kernel-memory disclosure.\nI:H - Attacker-chosen response bytes are written beyond the validated sink into adjacent kernel memory, providing an exploitable out-of-bounds write capable of modifying objects or achieving kernel code execution.\nA:H - The overwrite can corrupt critical kernel objects or reach invalid memory, causing an oops or panic; bounded FRWR sinks still permit connection-terminating denial of service."
    }
  }
}