{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "eb5dfcb9e36d0e46089fec777d911313c1876fa3"
            },
            {
              "fixed": "14d52c15d5d99477b20a2d61fe36f347080da6cd"
            },
            {
              "fixed": "d8957545fe96f7905791c937758ebfc1ae1e5b17"
            },
            {
              "fixed": "f687394af983df5660b6afae7e0d06969f3af206"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.15.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89571.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/features: bound fwctl command payload to the input buffer\n\nfwctl_cmd_rpc() copies cmd-\u003ein_len bytes into inbuf = kvzalloc(cmd-\u003ein_len)\nand passes inbuf and in_len to -\u003efw_rpc(). The CXL callback cxlctl_fw_rpc()\nignores in_len and never checks the user-controlled op_size against it.\n\ncxlctl_set_feature() bounds op_size only from below\n(op_size \u003c= sizeof(feat_in-\u003ehdr)) and then reads op_size - sizeof(hdr)\nbytes from feat_in-\u003efeat_data via cxl_set_feature(). With a small in_len\nand a large op_size the first memcpy() already reads past the\nkvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox\npayload and sent to the device, and a large enough op_size can walk into\nunmapped memory and oops the kernel. The Get paths pin op_size to a fixed\nsize but likewise read the input struct without checking in_len.\n\nReject, at the single dispatch point, any request whose fixed header plus\nop_size does not fit in the copied-in buffer. The lower-bound test guards\nthe subtraction and ensures op_size was copied in before it is read.",
  "id": "CVE-2026-89571",
  "modified": "2026-09-13T03:30:39.816952848Z",
  "published": "2026-09-11T19:44:40.328Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/14d52c15d5d99477b20a2d61fe36f347080da6cd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d8957545fe96f7905791c937758ebfc1ae1e5b17"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f687394af983df5660b6afae7e0d06969f3af206"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89571.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89571"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "cxl/features: bound fwctl command payload to the input buffer"
}