USB Device driver core defect

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USB Device driver core defect

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timias
Contributor IV

During my testing which consisted of disconnecting and reconnecting a Kinetis K60DN512 (MQX 4.0) USB port to Windows XP machine repeatedly, I was able to repeatedly generate a hard fault which locked up my processor.

I traced the defect to the khci_dev_main.c file specifically in the _usb_device_usbfs_service_tk_dne_intr function

My testing caused this function to be called with the direction set to USB_RECV. When this happened, It was possible to have

USB_XD_QUEUE_GET_HEAD(&state_ptr->EP_INFO[ep_num].xd_queue_recv,

  &xd_ptr);

return the xd_ptr as a NULL. The code isn't hardened against this and it crashed.

By adding:

if (xd_ptr != NULL)

{

    

} <- put this before: " if ( _usb_device_usbfs_process_receive_request(state_ptr,ep_num,stat,&buffer_ptr)!=USB_OK)"

seems to prevent the crash, it needs to be reviewed by the developers, becasue I think a more elegant solution is needed.

a similar problem seems to be in _usb_device_usbfs_service_tk_dne_intr, but my testing didn't indicate that that function was being called on quick reconnects.

This problem also exists in MQX 3.8, but the file name is different

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c0170
Senior Contributor III

Hello Robert Hodson,

Firstly thank you for taking time to report this :smileywink:  I am going to find out more about these bugs in code . I will let you know the result eventually.

Regards,

MartinK

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