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GHSA-HCR8-X92W-Q652

Vulnerability from github – Published: 2026-02-14 18:30 – Updated: 2026-03-17 21:31
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work

hci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling hci_uart_register_dev(), which calls proto->open() to initialize hu->priv. However, if a TTY write wakeup occurs during this window, hci_uart_tx_wakeup() may schedule write_work before hu->priv is initialized, leading to a NULL pointer dereference in hci_uart_write_work() when proto->dequeue() accesses hu->priv.

The race condition is:

CPU0 CPU1 ---- ---- hci_uart_set_proto() set_bit(HCI_UART_PROTO_INIT) hci_uart_register_dev() tty write wakeup hci_uart_tty_wakeup() hci_uart_tx_wakeup() schedule_work(&hu->write_work) proto->open(hu) // initializes hu->priv hci_uart_write_work() hci_uart_dequeue() proto->dequeue(hu) // accesses hu->priv (NULL!)

Fix this by moving set_bit(HCI_UART_PROTO_INIT) after proto->open() succeeds, ensuring hu->priv is initialized before any work can be scheduled.

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-23146"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-14T16:15:54Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work\n\nhci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling\nhci_uart_register_dev(), which calls proto-\u003eopen() to initialize\nhu-\u003epriv. However, if a TTY write wakeup occurs during this window,\nhci_uart_tx_wakeup() may schedule write_work before hu-\u003epriv is\ninitialized, leading to a NULL pointer dereference in\nhci_uart_write_work() when proto-\u003edequeue() accesses hu-\u003epriv.\n\nThe race condition is:\n\n  CPU0                              CPU1\n  ----                              ----\n  hci_uart_set_proto()\n    set_bit(HCI_UART_PROTO_INIT)\n    hci_uart_register_dev()\n                                    tty write wakeup\n                                      hci_uart_tty_wakeup()\n                                        hci_uart_tx_wakeup()\n                                          schedule_work(\u0026hu-\u003ewrite_work)\n      proto-\u003eopen(hu)\n        // initializes hu-\u003epriv\n                                    hci_uart_write_work()\n                                      hci_uart_dequeue()\n                                        proto-\u003edequeue(hu)\n                                          // accesses hu-\u003epriv (NULL!)\n\nFix this by moving set_bit(HCI_UART_PROTO_INIT) after proto-\u003eopen()\nsucceeds, ensuring hu-\u003epriv is initialized before any work can be\nscheduled.",
  "id": "GHSA-hcr8-x92w-q652",
  "modified": "2026-03-17T21:31:41Z",
  "published": "2026-02-14T18:30:14Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23146"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/03e8c90c62233382042b7bd0fa8b8900552fdb62"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0c3cd7a0b862c37acbee6d9502107146cc944398"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/186d147cf7689ba1f9b3ddb753ab634a84940cc9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/53e54cb31e667fca05b1808b990eac0807d1dab0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/937a573423ce5a96fdb1fd425dc6b8d8d4ab5779"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b0a900939e7e4866d9b90e9112514b72c451e873"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ccc683f597ceb28deb966427ae948e5ac739a909"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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