net: ethernet: mtk_ppe: avoid NULL deref when gmac0 is disabled

{
  "id": "cc980241c9f8cf4e99144e4606074d8f5ec616cc73e7f9dda506ed36ff279185",
  "url": "https://osv.dev/vulnerability/CVE-2026-31736",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net: ethernet: mtk_ppe: avoid NULL deref when gmac0 is disabled",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net: ethernet: mtk_ppe: avoid NULL deref when gmac0 is disabled If the gmac0 is disabled, the precheck for a valid ingress device will cause a NULL pointer deref and crash the system. This happens because eth->netdev[0] will be NULL but the code will directly try to access netdev_ops. Instead of just checking for the first net_device, it must be checked if any of the mtk_eth net_devices is matching the netdev_ops of the ingress device.",
    "evidence": "osv:CVE-2026-31736",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.81",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.22",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.12",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-31736",
      "aliases": [
        "CVE-2026-31736"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "73cfd947dbdb25ef9863ac49c4596a7d53ad4025"
                },
                {
                  "fixed": "0b832aad33e6f160fda310f0306a6483d85e9d6e"
                },
                {
                  "fixed": "5dff799c677152dde963c3917bacd9127b03e145"
                },
                {
                  "fixed": "7b2380f0a0e374010c1a4a13203511b9dee5b166"
                },
                {
                  "fixed": "976ff48c2ac6e6b25b01428c9d7997bcd0fb2949"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31736.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.11.0"
                },
                {
                  "fixed": "6.12.81"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.22"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "6.19.12"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31736.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:43.219978610Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0b832aad33e6f160fda310f0306a6483d85e9d6e",
        "https://git.kernel.org/stable/c/5dff799c677152dde963c3917bacd9127b03e145",
        "https://git.kernel.org/stable/c/7b2380f0a0e374010c1a4a13203511b9dee5b166",
        "https://git.kernel.org/stable/c/976ff48c2ac6e6b25b01428c9d7997bcd0fb2949",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31736.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31736",
        "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/2026/31xxx/CVE-2026-31736.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31736",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 510708,
  "published_at": "2026-05-01T14:14:33.583+00:00"
}