From: Cezary Rojewski <cezary.rojewski@xxxxxxxxx> [ Upstream commit 87978e6ad45a16835cc58234451111091be3c59a ] 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: Takashi Iwai <tiwai@xxxxxxxx> Signed-off-by: Cezary Rojewski <cezary.rojewski@xxxxxxxxx> Link: https://lore.kernel.org/r/20230119143235.1159814-1-cezary.rojewski@xxxxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- sound/pci/hda/hda_bind.c | 2 ++ sound/pci/hda/hda_codec.c | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c index 7af2515735957..8e35009ec25cb 100644 --- a/sound/pci/hda/hda_bind.c +++ b/sound/pci/hda/hda_bind.c @@ -144,6 +144,7 @@ static int hda_codec_driver_probe(struct device *dev) error: snd_hda_codec_cleanup_for_unbind(codec); + codec->preset = NULL; return err; } @@ -166,6 +167,7 @@ static int hda_codec_driver_remove(struct device *dev) if (codec->patch_ops.free) codec->patch_ops.free(codec); snd_hda_codec_cleanup_for_unbind(codec); + codec->preset = NULL; module_put(dev->driver->owner); return 0; } diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index f552785d301e0..19be60bb57810 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -791,7 +791,6 @@ void snd_hda_codec_cleanup_for_unbind(struct hda_codec *codec) snd_array_free(&codec->cvt_setups); snd_array_free(&codec->spdif_out); snd_array_free(&codec->verbs); - codec->preset = NULL; codec->follower_dig_outs = NULL; codec->spdif_status_reset = 0; snd_array_free(&codec->mixers); -- 2.39.0
