Fix hang on disconnect of non-compliant devices: Added timeout to RX path and buffer overflow check.

Author: wiredopposite

src/pio_usb.c

@@ -192,18 +192,25 @@ int __no_inline_not_in_flash_func(pio_usb_bus_receive_packet_and_handshake)(
   // timing critical start
   if (t > 0) {
     if (handshake == USB_PID_ACK) {
-      while ((pp->pio_usb_rx->irq & IRQ_RX_COMP_MASK) == 0) {
+      uint32_t timeout = 240;
+      while ((pp->pio_usb_rx->irq & IRQ_RX_COMP_MASK) == 0 && timeout--) {
         if (pio_sm_get_rx_fifo_level(pp->pio_usb_rx, pp->sm_rx)) {
           uint8_t data = pio_sm_get(pp->pio_usb_rx, pp->sm_rx) >> 24;
           crc_prev2 = crc_prev;
           crc_prev = crc;
           crc = update_usb_crc16(crc, data);
+          if (idx > (sizeof(pp->usb_rx_buffer) / sizeof(pp->usb_rx_buffer[0]))) {
+            return -1;
+          }
           pp->usb_rx_buffer[idx++] = data;
           crc_receive = (crc_receive >> 8) | (data << 8);
           crc_receive_inverse = crc_receive ^ 0xffff;
           crc_match = (crc_receive_inverse == crc_prev2);
         }
       }
+      if (timeout == 0) {
+        return -1;
+      }
 
       if (idx >= 4 && crc_match) {
         pio_usb_bus_send_handshake(pp, USB_PID_ACK);
@@ -212,10 +219,14 @@ int __no_inline_not_in_flash_func(pio_usb_bus_receive_packet_and_handshake)(
       }
     } else {
       // just discard received data since we NAK/STALL anyway
-      while ((pp->pio_usb_rx->irq & IRQ_RX_COMP_MASK) == 0) {
+      uint32_t timeout = 240;
+      while ((pp->pio_usb_rx->irq & IRQ_RX_COMP_MASK) == 0 && timeout--) {
         continue;
       }
       pio_sm_clear_fifos(pp->pio_usb_rx, pp->sm_rx);
+      if (timeout == 0) {
+        return -1;
+      }
 
       pio_usb_bus_send_handshake(pp, handshake);
     }