CVE-2026-80923
xhci: dbgtty: Fix unregister on tty_register_driver() failure
Description
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
INFO
Published Date :
Sept. 9, 2026, 5:17 p.m.
Last Modified :
Sept. 9, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to include the fix.
- Ensure the driver pointer is set to NULL on failure.
- Verify correct reference counting for the TTY driver.
- Test module load and unload sequences.
References to Advisories, Solutions, and Tools
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CWE - Common Weakness Enumeration
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associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-80923
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following table lists the changes that have been made to the
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Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 09, 2026
Action Type Old Value New Value Added Description 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 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80923.json">CVE-2026-80923</a> Added Reference https://git.kernel.org/stable/c/01b7bc0938061f2fd46e0094f6483d8c6c02f7d3 Added Reference https://git.kernel.org/stable/c/0d0faf3cc44c4d86fc6faf5cea972c0fbe00b922 Added Reference https://git.kernel.org/stable/c/0e469b94fbba8eb03666da41dd1082b793c50c1a Added Reference https://git.kernel.org/stable/c/33ed35ca629477f57e0dd1d77d6df96cf5a9eb55 Added Reference https://git.kernel.org/stable/c/43635ff6401ca0e0ed21875379eeded921321525 Added Reference https://git.kernel.org/stable/c/943f976c93e70563b132f5585ff68b08c89641a2 Added Reference https://git.kernel.org/stable/c/a916fa66a43e10f63198b6ce978badffc678821a Added Reference https://git.kernel.org/stable/c/eaca2814f32b9872a332326324b9e83e01f156d2