CVE-2026-52909 ip6_vti: set netns_immutable on the fallback device.

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/ipv6/ip6_vti.c"
    ],
    "versions": [
      {
        "version": "61220ab349485d911083d0b7990ccd3db6c63297",
        "lessThan": "ecf8904067dcba0dad86ece80874841e60317885",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "61220ab349485d911083d0b7990ccd3db6c63297",
        "lessThan": "dcdce3bc9f08026ff3739ee7339e1bef526fc5f3",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "61220ab349485d911083d0b7990ccd3db6c63297",
        "lessThan": "d289d5307762d1838aaece22c6b6fcad9e8865f9",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/ipv6/ip6_vti.c"
    ],
    "versions": [
      {
        "version": "3.15",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "3.15",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "6.18.36",
        "lessThanOrEqual": "6.18.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "7.0.13",
        "lessThanOrEqual": "7.0.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "7.1",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]