Messages in this thread | | | Subject | Re: [PATCH v1 1/1] USB: serial: Add boundry check for read_urbs array access | From | Oliver Neukum <> | Date | Thu, 08 Mar 2018 09:54:57 +0100 |
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Am Mittwoch, den 07.03.2018, 13:41 -0800 schrieb sathyanarayanan kuppuswamy : > > On 03/07/2018 12:58 PM, Greg KH wrote:
> > So I don't see why your check is needed, what other code path would ever > > call this function in a way that the bounds check would be needed? > void usb_serial_generic_read_bulk_callback(struct urb *urb) > > 385 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) { > 386 if (urb == port->read_urbs[i]) > 387 break; > 388 } > > In here, after this for loop is done (without any matching urb), i value > will be equal to ARRAY_SIZE(port->read_urbs). So there is a possibility > of usb_serial_generic_submit_read_urb() getting called with this invalid > index.
If this happens the function was called for a stray URB. Your check comes to late. We have called set_bit with an invalid index and other shit. We definitely do not just want to return an error in that case.
Regards Oliver
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