Re: kmemleak report on isp1763 and sierra MC8705

From: Ben Hutchings
Date: Sun Nov 25 2012 - 09:25:13 EST


On Tue, 2012-11-20 at 17:15 -0800, Greg Kroah-Hartman wrote:
> 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.

Also queued up for 3.2.

Ben.

--
Ben Hutchings
Never attribute to conspiracy what can adequately be explained by stupidity.

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