{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2023-53522",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2023-53522"
  ],
  "published": "2025-10-01T11:50:00Z",
  "summary": "cgroup,freezer: hold cpu_hotplug_lock before freezer_mutex",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup,freezer: hold cpu_hotplug_lock before freezer_mutex\n\nsyzbot is reporting circular locking dependency between cpu_hotplug_lock\nand freezer_mutex, for commit f5d39b020809 (\"freezer,sched: Rewrite core\nfreezer logic\") replaced atomic_inc() in freezer_apply_state() with\nstatic_branch_inc() which holds cpu_hotplug_lock.\n\ncpu_hotplug_lock => cgroup_threadgroup_rwsem => freezer_mutex\n\n  cgroup_file_write() {\n    cgroup_procs_write() {\n      __cgroup_procs_write() {\n        cgroup_procs_write_start() {\n          cgroup_attach_lock() {\n            cpus_read_lock() {\n              percpu_down_read(&cpu_hotplug_lock);\n            }\n            percpu_down_write(&cgroup_threadgroup_rwsem);\n          }\n        }\n        cgroup_attach_task() {\n          cgroup_migrate() {\n            cgroup_migrate_execute() {\n              freezer_attach() {\n                mutex_lock(&freezer_mutex);\n                (...snipped...)\n              }\n            }\n          }\n        }\n        (...snipped...)\n      }\n    }\n  }\n\nfreezer_mutex => cpu_hotplug_lock\n\n  cgroup_file_write() {\n    freezer_write() {\n      freezer_change_state() {\n        mutex_lock(&freezer_mutex);\n        freezer_apply_state() {\n          static_branch_inc(&freezer_active) {\n            static_key_slow_inc() {\n              cpus_read_lock();\n              static_key_slow_inc_cpuslocked();\n              cpus_read_unlock();\n            }\n          }\n        }\n        mutex_unlock(&freezer_mutex);\n      }\n    }\n  }\n\nSwap locking order by moving cpus_read_lock() in freezer_apply_state()\nto before mutex_lock(&freezer_mutex) in freezer_change_state().",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.21-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v6",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v8",
            "binary_version": "1:6.1.21-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.21-1+rpt1": {
            "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed",
            "upstream_version": "6.1.21",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.25"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-53522"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3756171b97c307d9df8b8ded1d883eec30172085"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/34fbb7b45bae20b551dda24337c7761ca13ce69d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/57dcd64c7e036299ef526b400a8d12b8a2352f26"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}