On 17-02-06 16:25:20, Ben Hutchings wrote:
> On Mon, Feb 06, 2017 at 04:09:18PM +0000, David Laight wrote:
> > From: Ben Hutchings
> [...]
> > > + ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
> > > +                       RTL8150_REQ_GET_REGS, RTL8150_REQT_READ,
> > > +                       indx, 0, buf, size, 500);
> > > + if (ret > 0 && ret <= size)
> > > +         memcpy(data, buf, ret);
> > 
> > If ret > size something is horridly wrong.
> > Silently not updating the callers buffer at all cannot be right.
> 
> Yes, it seems strange to check this.  I originally wrote this as ret >
> 0, but then I checked the usbnet core and found __usbnet_read_cmd()
> has the second comparison as well.
> 
> > > + kfree(buf);
> > > + return ret;

Since we return what usb_control_msg() told us to return i assume the error 
code 
will be available to anybody who cares.

> > I can't help feeling that it would be better to add a wrapper to
> > usb_control_msg() that does the kmalloc() and memcpy()s and
> > drop that into all the call sites.
> 
> It might be.  Right now I'm trying to patch up a bunch of regressions rather 
> than argue over an API change.

Right, first thing first.

I am in favor of changing the API, but this should not happen in the stable 
releases.  I hope Greg will make up his mind and let us know.


cheers,
Petko
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to