CVE-2026-80923

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CVE-2026-80923

Summary: xhci: dbgtty: Fix unregister on tty_register_driver() failure

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

References: https://git.kernel.org/stable/c/01b7bc0938061f2fd46e0094f6483d8c6c02f7d3, https://git.kernel.org/stable/c/0d0faf3cc44c4d86fc6faf5cea972c0fbe00b922, https://git.kernel.org/stable/c/0e469b94fbba8eb03666da41dd1082b793c50c1a, https://git.kernel.org/stable/c/33ed35ca629477f57e0dd1d77d6df96cf5a9eb55, https://git.kernel.org/stable/c/43635ff6401ca0e0ed21875379eeded921321525, https://git.kernel.org/stable/c/943f976c93e70563b132f5585ff68b08c89641a2, https://git.kernel.org/stable/c/a916fa66a43e10f63198b6ce978badffc678821a, https://git.kernel.org/stable/c/eaca2814f32b9872a332326324b9e83e01f156d2, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80923.json, https://nvd.nist.gov/vuln/detail/CVE-2026-80923, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git