CVE-2026-90190 null_blk: use DEFINE_MUTEX for the file-scope mutex

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/block/null_blk/main.c"
    ],
    "versions": [
      {
        "version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
        "lessThan": "f9f4ca45c770b7eec83fea6c9b727b26e691b513",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
        "lessThan": "349903f7ee72f7ac5b7a98840d701b2082d140a3",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
        "lessThan": "0a8c2f7b95981913ac370683e34db4906970c210",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
        "lessThan": "c7dea90c9b4ef1dfbd2e4df36de180c76fd7c33c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
        "lessThan": "234117949da3b3f9705a21b66094f9f30bbe681d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "49c3b9266a718dbd73c42e004288b4bb2ea0ac0b",
        "lessThan": "017dac7670909eaea3eb36e6b3b5a8be9ce0a14d",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/block/null_blk/main.c"
    ],
    "versions": [
      {
        "version": "5.19",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.19",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "6.1.188",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "6.6.157",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "6.12.110",
        "lessThanOrEqual": "6.12.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "6.18.52",
        "lessThanOrEqual": "6.18.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "7.2.6",
        "lessThanOrEqual": "7.2.*",
        "status": "unaffected",
        "versionType": "semver"
      },
      {
        "version": "7.3-rc1",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]