CVE-2026-11893 Double free / use-after-free in Bouffalo Lab HCI driver send() error paths (hci_bflb)

The Bluetooth HCI driver for Bouffalo Lab on-chip BLE controllers BL60x/BL70x/BL61x, btbflbsend in drivers/bluetooth/hci/hcibflb.c, violates the bthcidriverapi.send buffer-ownership contract. That contract documented at include/zephyr/drivers/bluetooth.h requires the buffer reference to be consum...