Re: [PATCH v2] cpufreq/pasemi: fix an use-after-free inpas_cpufreq_cpu_init()

[wen.yang99 at zte.com.cn]

> > The cpu variable is still being used in the of_get_property() call
> > after the of_node_put() call, which may result in use-after-free.
> >
> > Fixes: a9acc26b75f ("cpufreq/pasemi: fix possible object reference leak")
> > Signed-off-by: Wen Yang <wen.yang99 at zte.com.cn>
> > Cc: "Rafael J. Wysocki" <rjw at rjwysocki.net>
> > Cc: Viresh Kumar <viresh.kumar at linaro.org>
> > Cc: linuxppc-dev at lists.ozlabs.org
> > Cc: linux-pm at vger.kernel.org
> > Cc: linux-kernel at vger.kernel.org
> > ---
> > v2: clean up the code according to the advice of viresh.
> >
> >  drivers/cpufreq/pasemi-cpufreq.c | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/cpufreq/pasemi-cpufreq.c b/drivers/cpufreq/pasemi-cpufreq.c
> > index 6b1e4ab..c6d464b 100644
> > --- a/drivers/cpufreq/pasemi-cpufreq.c
> > +++ b/drivers/cpufreq/pasemi-cpufreq.c
> > @@ -128,20 +128,18 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
> >      int cur_astate, idx;
> >      struct resource res;
> >      struct device_node *cpu, *dn;
> > -    int err = -ENODEV;
> > +    int err;
> >
> >      cpu = of_get_cpu_node(policy->cpu, NULL);
> > -
> > -    of_node_put(cpu);
> >      if (!cpu)
> > -        goto out;
> > +        return -ENODEV;
> >
> 
> 
> >      dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
> >      if (!dn)
> >          dn = of_find_compatible_node(NULL, NULL,
> >                           "pasemi,pwrficient-sdc");
> >      if (!dn)
> > -        goto out;
> > +        return -ENODEV;
> 
> This change looks incorrect. You still need to drop reference to cpu ?
>

Thanks!
We will fix it immediately.

--
Thanks and regards,
Wen