{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2023-54210",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2023-54210"
  ],
  "published": "2025-12-30T12:14:19Z",
  "summary": "Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Avoid use-after-free in dbg for hci_remove_adv_monitor()\n\nKASAN reports that there's a use-after-free in\nhci_remove_adv_monitor(). Trawling through the disassembly, you can\nsee that the complaint is from the access in bt_dev_dbg() under the\nHCI_ADV_MONITOR_EXT_MSFT case. The problem case happens because\nmsft_remove_monitor() can end up freeing the monitor\nstructure. Specifically:\n  hci_remove_adv_monitor() ->\n  msft_remove_monitor() ->\n  msft_remove_monitor_sync() ->\n  msft_le_cancel_monitor_advertisement_cb() ->\n  hci_free_adv_monitor()\n\nLet's fix the problem by just stashing the relevant data when it's\nstill valid.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "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": "6.1.42"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-54210"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0d4d6b083da9b033ddccef72d77f373c819ae3ea"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bf00c2c8f6254f44ac041aa9a311ae9e0caf692b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/de6dfcefd107667ce2dbedf4d9337f5ed557a4a1"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:24:39Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The vulnerable code is reached only through a local `AF_BLUETOOTH` HCI control socket carrying `MGMT_OP_REMOVE_ADV_MONITOR` (or via bluetoothd acting on a local D-Bus client); no Bluetooth peer, radio frame, or network packet participates in triggering the free-then-read.\nAC:L - The attacker deterministically drives the sequence by adding an advertisement monitor and then removing it \u2014 no race must be won, and on MSFT-capable controllers (Intel/Realtek/Qualcomm/MediaTek, i.e. most real hardware) the offending branch is the default path.\nPR:L - The mgmt handler nominally requires a trusted socket, but on stock Linux/ChromeOS systems an unprivileged local user drives the exact same add/remove monitor sequence through BlueZ's AdvertisementMonitorManager1 D-Bus interface, and monitors are auto-removed when the unprivileged client disconnects.\nUI:N - The attacking process performs the register/unregister sequence itself; no victim action, mount, or file open is needed.\nS:U - The freed object, the stale read, and the resulting impact all live in the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is a use-after-free read of a freed slab object whose contents can be groomed during the sleeping `msft_remove_addr_filters_sync()` window, and the recycled heap contents are emitted into the kernel log \u2014 a repeatable heap-disclosure primitive usable against KASLR.\nI:H - Use-after-free of a `struct adv_monitor` with an attacker-influenceable reallocation window is a memory-corruption class defect; the dangling reference to a reclaimed slab object is the standard building block for heap-spray driven corruption.\nA:H - Dereferencing the freed monitor oopses the kernel when the backing slab page has been returned to the page allocator or under KASAN/panic_on_warn, and the sequence can be repeated at will to crash the system."
    }
  }
}