linux-kernel - Re: [PATCH 1/2] opp: fix of_node leak for unsupported entries

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Date:   Tue, 7 Jan 2020 15:04:49 +0100
From:   Michał Mirosław <mirq-linux@...e.qmqm.pl>
To:     Viresh Kumar <viresh.kumar@...aro.org>
Cc:     Nishanth Menon <nm@...com>, Stephen Boyd <sboyd@...nel.org>,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] opp: fix of_node leak for unsupported entries

On Tue, Jan 07, 2020 at 12:06:16PM +0530, Viresh Kumar wrote:
> Discard my earlier reply, it wasn't accurate/correct.
> 
> On 03-01-20, 20:36, Michał Mirosław wrote:
> > When parsing OPP v2 table, unsupported entries return NULL from
> > _opp_add_static_v2().
> 
> Right, as we don't want parsing to fail here.
> 
> > In this case node reference is leaked.
> 
> Why do you think so ?

for_each_available_child_of_node() returns nodes with refcount
increased, and _opp_add_static_v2() returning NULL does not store the
pointer anywhere - the created (temporary) OPP structure is freed,
but _opp_free() does not release node at opp->np.

I guess maybe the _opp_free() should be fixed instead?

Best Regards,
Michał Mirosław