Re: kmemleak report on isp1763 and sierra MC8705

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Nov 14, 2012 at 06:52:18PM +0100, Johan Hovold wrote:
> On Wed, Nov 14, 2012 at 12:12:01PM -0500, Richard Retanubun wrote:
> > On 10/11/12 09:30 AM, Johan Hovold wrote:
> > Hi Johan,
> > 
> > > There was a reference-count fix for the probe error path that went in to
> > > v3.5. Haven't read all the details on how you trigger your leak, but at
> > > the face of it, it could be related.
> > >
> > > Have a look at 0658a3366db7e27fa ("usb: use usb_serial_put in
> > > usb_serial_probe errors). If related, you should be seeing "Ignoring
> > > blacklisted interface #n" messages when you enable debug (e.g. #define
> > > DEBUG) in the sierra driver.
> > 
> > That was it! Thanks so much for the research.
> > I can apply it cleanly to 3.0.22 and see usb_release_dev() being
> > called and thus no more kmemleak.
> > 
> > >
> > > Greg, it seems to me that the fix referred to above should be backported
> > > to the earlier stable trees either way.
> > I would vote "yes" for this also.
> > 
> > While my setup circumstances may be a corner case, (modem kept
> > resetting to re-establish PPP connection) it was leaking 1192 bytes
> > per occurrence.
> 
> The leak affects every failed probe, for example due to blacklisted
> interfaces which is quite common, so commit 0658a3366db7 ("usb: use
> usb_serial_put in usb_serial_probe errors) should be backported to the
> <= 3.4 stable trees.

Thanks, now applied.

greg k-h