GHSA-M8FV-JWWG-RHRM

Vulnerability from github – Published: 2026-09-09 18:32 – Updated: 2026-09-09 18:32
VLAI
Details

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

xhci: dbgtty: Fix unregister on tty_register_driver() failure

If tty_register_driver() fails, it drops the reference, but fails to set the global dbc_tty_driver to NULL, causing the unregister to be called again when module exits.

On module unload dbc_tty_exit() only gates its cleanup on the driver pointer being non-NULL, so it operates on the already-freed driver:

module_init(xhci_hcd_init)
  xhci_hcd_init()
    xhci_dbc_init()                       [return value ignored]
      dbc_tty_init()
        tty_register_driver() fails
          tty_driver_kref_put()           -> driver freed
          (dbc_tty_driver left dangling)
...
module_exit(xhci_hcd_fini)
  xhci_hcd_fini()
    xhci_dbc_exit()
      dbc_tty_exit()
        if (dbc_tty_driver)               -> true (dangling)
          tty_unregister_driver()         -> use-after-free
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{
  "affected": [],
  "aliases": [
    "CVE-2026-80923"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-09T17:17:47Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxhci: dbgtty: Fix unregister on tty_register_driver() failure\n\nIf tty_register_driver() fails, it drops the reference, but fails to set\nthe global dbc_tty_driver to NULL, causing the unregister to be called\nagain when module exits.\n\nOn module unload dbc_tty_exit() only gates its cleanup on the driver\npointer being non-NULL, so it operates on the already-freed driver:\n\n    module_init(xhci_hcd_init)\n      xhci_hcd_init()\n        xhci_dbc_init()                       [return value ignored]\n          dbc_tty_init()\n            tty_register_driver() fails\n              tty_driver_kref_put()           -\u003e driver freed\n              (dbc_tty_driver left dangling)\n    ...\n    module_exit(xhci_hcd_fini)\n      xhci_hcd_fini()\n        xhci_dbc_exit()\n          dbc_tty_exit()\n            if (dbc_tty_driver)               -\u003e true (dangling)\n              tty_unregister_driver()         -\u003e use-after-free",
  "id": "GHSA-m8fv-jwwg-rhrm",
  "modified": "2026-09-09T18:32:04Z",
  "published": "2026-09-09T18:32:04Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80923"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/01b7bc0938061f2fd46e0094f6483d8c6c02f7d3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0d0faf3cc44c4d86fc6faf5cea972c0fbe00b922"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0e469b94fbba8eb03666da41dd1082b793c50c1a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/33ed35ca629477f57e0dd1d77d6df96cf5a9eb55"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/43635ff6401ca0e0ed21875379eeded921321525"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/943f976c93e70563b132f5585ff68b08c89641a2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a916fa66a43e10f63198b6ce978badffc678821a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eaca2814f32b9872a332326324b9e83e01f156d2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}



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