Overview
About vulnerability
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
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 11 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU
- Affected packages:
- linux @ 5.10.259 (+4 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 13 | Will Not Fix |
17 kernels
|
| Oracle Linux 8 UEK 7 | Planned | — |
| Oracle Linux 9 UEK 7 | Planned | — |