• Cezary Rojewski's avatar
    ALSA: hda: Do not unset preset when cleaning up codec · 87978e6a
    Cezary Rojewski authored
    Several functions that take part in codec's initialization and removal
    are re-used by ASoC codec drivers implementations. Drivers mimic the
    behavior of hda_codec_driver_probe/remove() found in
    sound/pci/hda/hda_bind.c with their component->probe/remove() instead.
    
    One of the reasons for that is the expectation of
    snd_hda_codec_device_new() to receive a valid pointer to an instance of
    struct snd_card. This expectation can be met only once sound card
    components probing commences.
    
    As ASoC sound card may be unbound without codec device being actually
    removed from the system, unsetting ->preset in
    snd_hda_codec_cleanup_for_unbind() interferes with module unload -> load
    scenario causing null-ptr-deref. Preset is assigned only once, during
    device/driver matching whereas ASoC codec driver's module reloading may
    occur several times throughout the lifetime of an audio stack.
    Suggested-by: default avatarTakashi Iwai <tiwai@suse.com>
    Signed-off-by: default avatarCezary Rojewski <cezary.rojewski@intel.com>
    Link: https://lore.kernel.org/r/20230119143235.1159814-1-cezary.rojewski@intel.comSigned-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    87978e6a
hda_codec.c 110 KB