Kees Cook wrote:
> Hi Németh,
>
> On Mon, Oct 11, 2010 at 08:54:04PM +0200, Németh Márton wrote:
>> There might be similar problem also in the case USB_DEVICE_ID_CODEMERCS_IOW56. There
>> is buf is allocated with usb_alloc_coherent() to the size dev->report_size. However,
>> some lines later the copy_from_user() function tries to copy "count" number of
>> bytes to the dev->report_size allocated buffer. Unfortunately I don't have such
>> devices to try the driver so these are just coming from "static analysis".
>
> I don't think the USB_DEVICE_ID_CODEMERCS_IOW56 path is a problem:
>
> if (count != dev->report_size) {
> retval = -EINVAL;
> goto exit;
> }
You are right, I missed this condition.
> switch (dev->product_id) {
> ...
> case USB_DEVICE_ID_CODEMERCS_IOW56:
> ...
> buf = usb_alloc_coherent(dev->udev, dev->report_size,
> GFP_KERNEL, &int_out_urb->transfer_dma);
> ...
> if (copy_from_user(buf, user_buffer, count)) {
>
> i.e. count must == dev->report_size, and the buf is allocated with size
> dev->report_size even though copy_from_user uses "count".
>
> -Kees
>
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