Re: [PATCH] cpufreq: Avoid a bad reference count on CPU node

From: Rafael J. Wysocki
Date: Tue Oct 01 2024 - 14:49:47 EST


On Tue, Oct 1, 2024 at 8:32 AM Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
>
> On 17-09-24, 15:42, Miquel Sabaté Solà wrote:
> > In the parse_perf_domain function, if the call to
> > of_parse_phandle_with_args returns an error, then the reference to the
> > CPU device node that was acquired at the start of the function would not
> > be properly decremented.
> >
> > Address this by declaring the variable with the __free(device_node)
> > cleanup attribute.
> >
> > Signed-off-by: Miquel Sabaté Solà <mikisabate@xxxxxxxxx>
> > ---
> > include/linux/cpufreq.h | 6 +-----
> > 1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> > index d4d2f4d1d7cb..aabec598f79a 100644
> > --- a/include/linux/cpufreq.h
> > +++ b/include/linux/cpufreq.h
> > @@ -1113,10 +1113,9 @@ static inline int parse_perf_domain(int cpu, const char *list_name,
> > const char *cell_name,
> > struct of_phandle_args *args)
> > {
> > - struct device_node *cpu_np;
> > int ret;
> >
> > - cpu_np = of_cpu_device_node_get(cpu);
> > + struct device_node *cpu_np __free(device_node) = of_cpu_device_node_get(cpu);
> > if (!cpu_np)
> > return -ENODEV;
> >
> > @@ -1124,9 +1123,6 @@ static inline int parse_perf_domain(int cpu, const char *list_name,
> > args);
> > if (ret < 0)
> > return ret;
> > -
> > - of_node_put(cpu_np);
> > -
> > return 0;
> > }
>
> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
>
> --

Applied as 6.12-rc material, thanks!