cxl/region: Fix null pointer dereference for resetting decoder

{
  "id": "b2ac01619f5740453d2355e81c6ed92259ce0cb4afc06388bfd1c4e0b362a943",
  "url": "https://osv.dev/vulnerability/CVE-2022-48707",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "cxl/region: Fix null pointer dereference for resetting decoder",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: cxl/region: Fix null pointer dereference for resetting decoder Not all decoders have a reset callback. The CXL specification allows a host bridge with a single root port to have no explicit HDM decoders. Currently the region driver assumes there are none. As such the CXL core creates a special pass through decoder instance without a commit/reset callback. Prior to this patch, the ->reset() callback was called unconditionally when calling cxl_region_decode_reset. Thus a configuration with 1 Host Bridge, 1 Root Port, and one directly attached CXL type 3 device or multiple CXL type 3 devices attached to downstream ports of a switch can cause a null pointer dereference. Before the fix, a kernel crash was observed when we destroy the region, and a pass through decoder is reset. The issue can be reproduced as below, 1) create a region with a CXL setup which includes a HB with a single root port under which a memdev is attached directly. 2) destroy the region with cxl destroy-region regionX -f.",
    "evidence": "osv:CVE-2022-48707",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.12",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2022-48707",
      "aliases": [
        "CVE-2022-48707"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "176baefb2eb5d7a3ddebe3ff803db1fce44574b5"
                },
                {
                  "fixed": "a04c7d062b537ff787d00da95bdfe343260d4beb"
                },
                {
                  "fixed": "4fa4302d6dc7de7e8e74dc7405611a2efb4bf54b"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48707.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.0.0"
                },
                {
                  "fixed": "6.1.12"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48707.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.320220166Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/4fa4302d6dc7de7e8e74dc7405611a2efb4bf54b",
        "https://git.kernel.org/stable/c/a04c7d062b537ff787d00da95bdfe343260d4beb",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48707.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2022-48707",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48707.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2022-48707",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 509776,
  "published_at": "2024-05-21T15:22:48.735+00:00"
}