STM32F4xx HAL dumps RAM through UART on Framing Error? (possible security issue)

[SMisi]

I am using DMA for receiving data, but interrupts for transmitting over UART and I am experiencing following issue:

When the UART experiences Framing Error, the DMA stream triggers an interrupt to which HAL responds by eventually calling UART_DMAAbortOnError() which will zero both RX and TX transfer counters, but does not terminate the Interrupt driven transmission properly. If this happens during a transmission the UART interrupt handler calls UART_Transmit_IT() which contains following boundary check:

if (--huart->TxXferCount == 0U)

But the TxXferCount was set to 0 by the UART_DMAAbortOnError(), so the counter will wrap around and the UART will effectively dump half of the RAM.

Does anybody know the correct work-around, beside modifying HAL code?

Thanks

[Ozone]

> Does anybody know the correct work-around, beside modifying HAL code?

I think not.

It is best to consider Cube/HAL code as a free gift for beginners, and useful for rapid prototyping.

But it is unfit for serious commercial purposes.

[SMisi]

I eventually ended up disabling DMA using HAL_UART_DMAPause() and HAL_UART_DMAResume() while transmitting, since I did not need full-duplex communication. That seems to have helped.

[Tesla DeLorean]

It is certainly littered with stuff like this, but we keep hearing how it's MISRA, LINT'd or whatever.

And very little of it seems to have been real-world tested, stressed or gotten much QA scrutiny