CVE-2026-10642 Unbounded TX busy-loop DoS in Zephyr PL011 UART driver under CTS hardware flow control

The Zephyr PL011 UART driver drivers/serial/uartpl011.c contains an unbounded software loop in pl011irqtxenable that repeatedly invokes the interrupt-driven application callback while the TX interrupt mask bit PL011IMSCTXIM is set, to work around the controller's level-transition TX-interrupt...