Messages in this thread | | | Subject | Re: [PATCH v1 1/1] USB: serial: Add boundry check for read_urbs array access | From | sathyanarayanan kuppuswamy <> | Date | Thu, 8 Mar 2018 15:29:48 -0800 |
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On 03/08/2018 12:54 AM, Oliver Neukum wrote: > 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. In that case do you think we should use some WARN_ON() for invalid index in usb_serial_generic_read_bulk_callback()? > > Regards > Oliver > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
-- Sathyanarayanan Kuppuswamy Linux kernel developer
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