CVE-2026-68085
HighCVSS 8.0Exploitation Probability (EPSS)
Low risk17th percentile - higher than 17% of all known CVEs
Summary
In the Linux kernel, the Bluetooth hci_uart driver did not clear the HCI_UART_SENDING bit when canceling write_work, which blocked future writes after reopening the device. The fix clears this bit and safely cancels the work using disable_work_sync and enable_work.
Risk Assessment
The risk is that after closing and reopening a Bluetooth device, data transmission may be permanently blocked, leading to unavailability of communication functions.
Recommendation
It is recommended to apply the Linux kernel patch that clears the HCI_UART_SENDING bit and safely manages write_work.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_uart: clear HCI_UART_SENDING when write_work is canceled HCI_UART_SENDING bit in tx_state means write_work is pending and blocks queueing it again. Currently this bit is not cleared when canceling the work in hci_uart_close(), which blocks future writes when device is reopened later if write_work was pending. Fix by clearing HCI_UART_SENDING when canceling the work. Also make clearing of tx_skb safe by using disable_work_sync + enable_work instead of just cancel_work_sync. hci_uart_flush() purges the proto tx queue so we can cancel the pending write_work there, instead of doing it just in hci_uart_close(). Re-enable and possibly requeue the work after queue flush.