Function snd_pcm_create() will return a negative number when it fails to create a new PCM instance, thus its return value shall be checked before further manipulations of the created PCM. But in function lx_pcm_create(), at sound/pci/lx6464es/lx6464es.c:839, there is no checking of the return value of lx_pcm_create() at line 853, which may trigger an invalid memmory access error when dereferencing variable pcm at line 856.
The related codes in lx_pcm_create() are as following.
lx_pcm_create @@sound/pci/lx6464es/lx6464es.c:853
 853        err = snd_pcm_new(chip->card, (char *)card_name, 0,
 854                          1, 1, &pcm);
 855
 856        pcm->private_data = chip;

Generally, the return value of snd_pcm_create() shall be checked to make sure that the PCM instance is create successfully. Like the following codes from the same device driver.
snd_azf3328_pcm @@sound/pci/azt3328.c:2225
2225        err = snd_pcm_new(chip->card, "AZF3328 DSP", AZF_PCMDEV_STD,
2226                                                                1, 1, &pcm);
2227        if (err < 0)
2228                return err;
2229        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
2230                                                &snd_azf3328_playback_ops);


Thank you

RUC_Soft_Sec