net: enetc: fix NTMP DMA use-after-free issue

{
  "id": "603f2fe9ee8d6e036ead8c75a73aacef8b45db752a019b10dafbac1c0e5aa722",
  "url": "https://osv.dev/vulnerability/CVE-2026-53300",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net: enetc: fix NTMP DMA use-after-free issue",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net: enetc: fix NTMP DMA use-after-free issue The AI-generated review reported a potential DMA use-after-free issue [1]. If netc_xmit_ntmp_cmd() times out and returns an error, the pending command is not explicitly aborted, while ntmp_free_data_mem() unconditionally frees the DMA buffer. If the buffer has already been reallocated elsewhere, this may lead to silent memory corruption. Because the hardware eventually processes the pending command and perform a DMA write of the response to the physical address of the freed buffer. To resolve this issue, this patch does the following modifications: 1. Convert cbdr->ring_lock from a spinlock to a mutex The lock was originally a spinlock in case NTMP operations might be invoked from atomic context. After downstream support for all NTMP tables, no such usage has materialized. A mutex lock is now required because the driver now needs to reclaim used BDs and release associated DMA memory within the lock's context, while dma_free_coherent() might sleep. 2. Introduce software command BD (struct netc_swcbd) The hardware write-back overwrites the addr and len fields of the BD, so the driver cannot rely on the hardware BD to free the associated DMA memory. The driver now maintains a software shadow BD storing the DMA buffer pointer, DMA address, and size. And netc_xmit_ntmp_cmd() only reclaims older BDs when the number of used BDs reaches NETC_CBDR_CLEAN_WORK (16). The soft",
    "evidence": "osv:CVE-2026-53300",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.33",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-53300",
      "aliases": [
        "CVE-2026-53300"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                },
                {
                  "fixed": "37c8933064be714ee672b0a0523c2fd045b73b3d"
                },
                {
                  "fixed": "655d9ce9b1d3db0aa5271acb5e5101c66bd0d58b"
                },
                {
                  "fixed": "3cade698881eb238f88cbbfec82acc2110440a3f"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53300.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.16.0"
                },
                {
                  "fixed": "6.18.33"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53300.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:21.811705746Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/37c8933064be714ee672b0a0523c2fd045b73b3d",
        "https://git.kernel.org/stable/c/3cade698881eb238f88cbbfec82acc2110440a3f",
        "https://git.kernel.org/stable/c/655d9ce9b1d3db0aa5271acb5e5101c66bd0d58b",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53300.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-53300",
        "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/2026/53xxx/CVE-2026-53300.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-53300",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 487986,
  "published_at": "2026-06-26T19:40:57.186+00:00"
}