On Tuesday, July 9, 2019 10:12:05 AM CEST Viresh Kumar wrote:
> On 09-07-19, 16:04, Wen Yang wrote:
> > 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.yan...@zte.com.cn>
> > Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
> > Cc: Viresh Kumar <viresh.ku...@linaro.org>
> > Cc: Michael Ellerman <m...@ellerman.id.au>
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Cc: linux...@vger.kernel.org
> > Cc: linux-ker...@vger.kernel.org
Patch applied.
> > ---
> > v5: put together the code to get, use, and release cpu device_node.
> > v4: restore the blank line.
> > v3: fix a leaked reference.
> > v2: clean up the code according to the advice of viresh.
> >
> > drivers/cpufreq/pasemi-cpufreq.c | 21 +++++++++------------
> > 1 file changed, 9 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/cpufreq/pasemi-cpufreq.c
> > b/drivers/cpufreq/pasemi-cpufreq.c
> > index 6b1e4ab..1f0beb7 100644
> > --- a/drivers/cpufreq/pasemi-cpufreq.c
> > +++ b/drivers/cpufreq/pasemi-cpufreq.c
> > @@ -131,10 +131,17 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy
> > *policy)
> > int err = -ENODEV;
> >
> > cpu = of_get_cpu_node(policy->cpu, NULL);
> > -
> > - of_node_put(cpu);
> > if (!cpu)
> > goto out;
>
> I would have loved a blank line here :)
And I added the blank line.
> > + max_freqp = of_get_property(cpu, "clock-frequency", NULL);
> > + of_node_put(cpu);
> > + if (!max_freqp) {
> > + err = -EINVAL;
> > + goto out;
> > + }
> > +
> > + /* we need the freq in kHz */
> > + max_freq = *max_freqp / 1000;
> >
> > dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
> > if (!dn)
> > @@ -171,16 +178,6 @@ static int pas_cpufreq_cpu_init(struct cpufreq_policy
> > *policy)
> > }
> >
> > pr_debug("init cpufreq on CPU %d\n", policy->cpu);
> > -
> > - max_freqp = of_get_property(cpu, "clock-frequency", NULL);
> > - if (!max_freqp) {
> > - err = -EINVAL;
> > - goto out_unmap_sdcpwr;
> > - }
> > -
> > - /* we need the freq in kHz */
> > - max_freq = *max_freqp / 1000;
> > -
> > pr_debug("max clock-frequency is at %u kHz\n", max_freq);
> > pr_debug("initializing frequency table\n");
>
> Though, enough versions have happened now.
>
> Acked-by: Viresh Kumar <viresh.ku...@linaro.org>
>
>
Thanks!
