STM32 CanBus cannot get out of interrupt handler

hello dear forum,

I try to make CANBUS of STM32F103RC work
I managed to make CANBUS send message in loopback mode
however when I turn on receive interrupt
the processor hangs at first message and watchdog resets the micro
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 CAN_ITConfig(CAN1, CAN_IT_FMP0, ENABLE);
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I suspect the code enters the interrupt handler and cannot leave it
I want to ask how do I fill following lines to reset interupt flag and 
pending bit
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void USB_LP_CAN1_RX0_IRQHandler(void)
{
CAN_ClearFlag(CAN1, ??????????);
CAN_ClearITPendingBit(CAN1,??????????);

  CanRxMsg RxMessage;

  CAN_Receive(CAN1, CAN_FIFO0, &RxMessage);
---------------------------------------------
thank you