CVE-2022-48741 ovl: fix NULL pointer dereference in copy up warning

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/overlayfs/copy_up.c"
    ],
    "versions": [
      {
        "version": "5cffa333a2b263821561328cc75a3ffc8097d093",
        "lessThan": "e6b678c1a3673de6a5d2f4e22bb725a086a0701a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "5b0a414d06c3ed2097e32ef7944a4abb644b89bd",
        "lessThan": "9c7f8a35c5a83740c0e3ea540b6ad145c50d79aa",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "5b0a414d06c3ed2097e32ef7944a4abb644b89bd",
        "lessThan": "4ee7e4a6c9b298da44029ed9ec8ed23ae49cc209",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/overlayfs/copy_up.c"
    ],
    "versions": [
      {
        "version": "5.16",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.16",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.15.20",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.16.6",
        "lessThanOrEqual": "5.16.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "5.17",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]