CVE-2023-52456

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> serial: imx: fix tx statemachine deadlock<br /> <br /> When using the serial port as RS485 port, the tx statemachine is used to<br /> control the RTS pin to drive the RS485 transceiver TX_EN pin. When the<br /> TTY port is closed in the middle of a transmission (for instance during<br /> userland application crash), imx_uart_shutdown disables the interface<br /> and disables the Transmission Complete interrupt. afer that,<br /> imx_uart_stop_tx bails on an incomplete transmission, to be retriggered<br /> by the TC interrupt. This interrupt is disabled and therefore the tx<br /> statemachine never transitions out of SEND. The statemachine is in<br /> deadlock now, and the TX_EN remains low, making the interface useless.<br /> <br /> imx_uart_stop_tx now checks for incomplete transmission AND whether TC<br /> interrupts are enabled before bailing to be retriggered. This makes sure<br /> the state machine handling is reached, and is properly set to<br /> WAIT_AFTER_SEND.