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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Fixes

Solution

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Workaround

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History

Wed, 09 Sep 2026 16:30:00 +0000

Type Values Removed Values 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
Title xhci: dbgtty: Fix unregister on tty_register_driver() failure
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-09T16:19:43.538Z

Reserved: 2026-08-26T14:34:25.801Z

Link: CVE-2026-80923

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-09T17:17:47.507

Modified: 2026-09-09T17:17:47.507

Link: CVE-2026-80923

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

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