[alsa-devel] [bug report] ASoC: snd_soc_component_driver has snd_compr_ops

[Dan Carpenter]

Hello Kuninori Morimoto,

The patch 9e7e3738ab0e: "ASoC: snd_soc_component_driver has
snd_compr_ops" from Oct 11, 2017, leads to the following static
checker warning:

	sound/soc/soc-compress.c:109 soc_compr_open()
	warn: 'cstream->runtime->private_data' double freed

sound/soc/soc-compress.c
    91          return 0;
    92  
    93  machine_err:
    94          for_each_rtdcom(rtd, rtdcom) {
    95                  component = rtdcom->component;
    96  
    97                  /* ignore duplication for now */
    98                  if (platform && (component == &platform->component))
    99                          continue;
   100  
   101                  if (!component->driver->compr_ops ||
   102                      !component->driver->compr_ops->free)
   103                          continue;
   104  
   105                  component->driver->compr_ops->free(cstream);
                                                    ^^^^^^^^^^^^^^^
This is in a loop so is the really right?  We end up freeing cstream
over and over?

   106          }
   107  
   108          if (platform && platform->driver->compr_ops && platform->driver->compr_ops->free)
   109                  platform->driver->compr_ops->free(cstream);
                                                    ^^^^^^^^^^^^^
This second call is what triggers the warning.

   110  plat_err:
   111          if (cpu_dai->driver->cops && cpu_dai->driver->cops->shutdown)
   112                  cpu_dai->driver->cops->shutdown(cstream, cpu_dai);
   113  out:
   114          mutex_unlock(&rtd->pcm_mutex);
   115          return ret;
   116  }

regards,
dan carpenter