Re: [RESEND PATCH] cpufreq: unnecesary double free in pcc_cpufreq_do_osc

[Dave Jones <davej@redhat.com>]

On Thu, Sep 30, 2010 at 10:59:51PM +0300, Pekka Enberg wrote:
 > > +++ b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c
 > > @@ -379,6 +379,8 @@ static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
 > >        if (!(supported & 0x1))
 > >                return -ENODEV;
 > >
 > > +       return ret;
 > > +
 > >  out_free:
 > >        kfree(output.pointer);
 > >        return ret;
 > 
 > Where is the double free here? I can't see it. I do see memory leaks
 > happening in error handling paths of pcc_cpufreq_do_osc() which makes
 > me think we need something like the attached patch.

I think Dave's patch is correct.  There's a kfree(output.pointer) at line 359.
If we fall all the way through without hitting any of the return -ENODEVs,
we end up doing a 2nd kfree in the out_free:

	Dave