Linux Ethernet Bridging - Jul 2017 - [Bridge] [PATCH 1/1] bridge: mdb: report complete_info ptr as not a kmemleak

From: Eduardo Valentin <eduval at amazon.com>
Date: Mon, 3 Jul 2017 10:06:34 -0700
> We currently get the following kmemleak report:
 ...
> This patch flags the complete_info ptr object as not a leak as it will
> get freed when .complete_priv() is called,
We don't call .complete_priv().  We call .complete().

 for the br mdb case, it
> will be freed at br_mdb_complete().
> 
> Cc: stable <stable at vger.kernel.org> # v4.9+
> Reviewed-by: Vallish Vaidyeshwara <vallish at amazon.com>
> Signed-off-by: Eduardo Valentin <eduval at amazon.com>
I don't understand why kmemleak cannot see this.

We store the pointer globally when we do the switchdev_port_obv_add()
call and it should be able to see that.

On Tue, Jul 04, 2017 at 01:48:42AM -0700, David Miller
wrote:
> From: Eduardo Valentin <eduval at amazon.com>
> Date: Mon, 3 Jul 2017 10:06:34 -0700
> 
> > We currently get the following kmemleak report:
>  ...
> > This patch flags the complete_info ptr object as not a leak as it will
> > get freed when .complete_priv() is called,
> 
> We don't call .complete_priv().  We call .complete().
True, I can fix this wording in the commit next version.
> 
>  for the br mdb case, it
> > will be freed at br_mdb_complete().
> > 
> > Cc: stable <stable at vger.kernel.org> # v4.9+
> > Reviewed-by: Vallish Vaidyeshwara <vallish at amazon.com>
> > Signed-off-by: Eduardo Valentin <eduval at amazon.com>
> 
> I don't understand why kmemleak cannot see this.
> 
> We store the pointer globally when we do the switchdev_port_obv_add()
> call and it should be able to see that.
I see and agree. But even then I get these reports consistently on RTM_NEWMDB
type.
This is why I am proposing marking as a non-kmemleak.

To me, this is only a leak if .complete() never gets called.


-- 
All the best,
Eduardo Valentin