CVE-2026-53250 xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/xdp/xsk.c"
    ],
    "versions": [
      {
        "version": "48eb03dd26304c24f03bdbb9382e89c8564e71df",
        "lessThan": "0dfe05b938435892875e07771170051346412df9",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48eb03dd26304c24f03bdbb9382e89c8564e71df",
        "lessThan": "bfdfd2706d5fb2cd496a1506e680daf979309c8b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "48eb03dd26304c24f03bdbb9382e89c8564e71df",
        "lessThan": "22ba97ea9cc1f63a0d0244fae38057ed452b6ac7",
        "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/xdp/xsk.c"
    ],
    "versions": [
      {
        "version": "6.8",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.8",
        "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"
      }
    ]
  }
]