{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "9cb837480424e78ed585376f944088246685aec3"
            },
            {
              "fixed": "68c09762172f6224e9ddf9b0a60bacbb36e443eb"
            },
            {
              "fixed": "6cada540150894e81042a0ae0c796a21a9a877da"
            },
            {
              "fixed": "2912f3d40355dabc08fdbaaf2764d02445fe88dc"
            },
            {
              "fixed": "6f40246f4312fdbab5a13cc440adebf95eb2aa66"
            },
            {
              "fixed": "5a45d0aa1fa50a333ce5763ade744e2d89838667"
            },
            {
              "fixed": "da3e44add94b05dfde56f898421922f5cf35705f"
            },
            {
              "fixed": "963af8d97a8c6a117134a8d0db1415e0489200b1"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.8.0"
            },
            {
              "fixed": "5.15.212"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64269.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rtrs-srv: Bound RDMA-Write length to chunk size in rdma_write_sg\n\nWhen the server answers an RTRS READ, rdma_write_sg() builds the source\nscatter/gather entry for the IB_WR_RDMA_WRITE that returns data to the\npeer. Its length is taken directly from the wire descriptor:\n\n  plist-\u003elength = le32_to_cpu(id-\u003erd_msg-\u003edesc[0].len);\n\nrd_msg points into the chunk buffer that the remote peer filled via\nRDMA-WRITE-WITH-IMM (rtrs_srv_rdma_done() -\u003e process_io_req() -\u003e\nprocess_read()), so desc[0].len is attacker-controlled and, before this\nchange, was only rejected when zero. The source address is the fixed\nchunk start (dma_addr[msg_id]) and the source lkey is the PD-wide\nlocal_dma_lkey, which is not tied to the chunk's MR mapping, so the verbs\nlayer does not constrain the transfer length to max_chunk_size. msg_id\nand off are bounded against queue_depth and max_chunk_size in\nrtrs_srv_rdma_done(), but desc[0].len is a separate field that was not\nchecked against the chunk size.\n\nA peer that advertises desc[0].len larger than max_chunk_size can make\nthe posted RDMA write read past the chunk's mapped region. The resulting\nbehaviour depends on the IOMMU configuration: with no IOMMU or in\npassthrough mode the read may extend into memory adjacent to the chunk\nand be returned to the peer, which can disclose host memory; with a\ntranslating IOMMU the out-of-range access is expected to fault and abort\nthe connection. In either case the transfer exceeds what the protocol\npermits and is driven by a remote peer.\n\nReject a descriptor length above max_chunk_size, mirroring the existing\noff \u003e= max_chunk_size bound in rtrs_srv_rdma_done(). Legitimate clients\ndo not exceed it: the client sets desc[0].len to its MR length, which is\ncapped at the negotiated max_io_size (max_chunk_size - MAX_HDR_SIZE).",
  "id": "CVE-2026-64269",
  "modified": "2026-07-27T03:56:16.911411849Z",
  "published": "2026-07-25T08:49:16.946Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2912f3d40355dabc08fdbaaf2764d02445fe88dc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5a45d0aa1fa50a333ce5763ade744e2d89838667"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/68c09762172f6224e9ddf9b0a60bacbb36e443eb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6cada540150894e81042a0ae0c796a21a9a877da"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6f40246f4312fdbab5a13cc440adebf95eb2aa66"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/963af8d97a8c6a117134a8d0db1415e0489200b1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/da3e44add94b05dfde56f898421922f5cf35705f"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64269.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64269"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "RDMA/rtrs-srv: Bound RDMA-Write length to chunk size in rdma_write_sg"
}